Transcripts
1. Introduction: Hi everyone, and welcome to Introduction to V effects with Houdini series, learning the basics. In this course, we will learn about side-effects who became the industry standard 3D application. I will show you how to get started from the ground up. We will learn everything from downloading and installing the free version of the software to learning the basics that made Houdini, the industry standard and visual effects and film, TV and video games. I was previously a visual effects artist for a feature link animation studio and worked on many feature films, including the book of life, free birds and rock dog. I've also worked on many special projects including and Universal Studios despicable Me the ride, Ice Age, a mammoth Christmas and many more. Please join me in learning about this great piece of software and starting your journey to make stunning visual effects. I'll see you in class.
2. Lesson 01: Install: Hey class, welcome back. So in this first lesson, what I want to show you is how you can actually install Houdini and how we can get started. Free version that you can download either to a Windows computer, a Mac, or Linux computer. So right now, I'm at the side effects website. So this is side-effects dot com. Side effects is the company that makes Houdini. And they have a really great website here. If you just kinda scroll down and scroll over, you can see a lot of, of, of different videos and images of tutorials down here. Customer stories, they have events. So it's a great place to learn about Houdini or anything. Houdini. You can visit this site. This would be the first place I would go to update your Houdini version. If you wanna get a commercial version later on, if you decide that you really like Houdini and you want to continue on with it, maybe to do actual projects to make money or anything like that. You can go into side-effects and check that out as well. If you go to products here, you can go down to Houdini. You can check out the overview, and then you can compare versions. Okay, so if I go to Compare, you can kinda come and see there's a commercial version, there's an indie version, which is kind of a, a freelance version that cost a lot less. But you can still make money off of it, use it for commercial projects and stuff like that. And then there's the learning version. The apprentice version is what we're going to be using in this class because that's the free version. There is an educational version that colleges and universities can use as well. So if you just go through here, you can see the differences between each one. The free one really has everything that the commercial has. The only difference is there's some, some rendering differences. There's a watermark. I think, I believe that you can only render up to 1280 by 720. But besides that, it's, it's just a really, really good deal to learn Houdini and kinda get a headstart. So if you do decide to go on with it or you decide to get another job using Houdini maybe at a studio, you kinda have a headstart. Okay, so that's just one thing to check out here. If you go up here, there's industries, you can check out the different industries that Houdini is a part of. Video games, film, TV, Motion graphics, virtual reality, all albeit components. That use Houdini. Because again, Houdini is a professional grade program. Ok? So remember that when you're learning it is a professional program. So this is Pixar Disney. You know, you name it. They, they use this program to make all their high-end visual effects and more. So. Here are the learning tab. You can check this out. There's tutorials, different learning paths. You can, you can check those out if there's some particular that you're looking for, maybe you need to know how to do. You can take a look at these learning paths community. There's a forum here. So you can ask questions on the forum. And there's a lot of professionals out there that will answer your questions and give you really good advice. Maybe share some actual Houdini files with you, with set-ups to help you get going. So it's a very, very good resource as far as learning and networking to, you know, getting, getting yourself out there and letting these professionals know what you wanna do and what you're interested in. So the form is always a great place to go. Support. Here's customer support. You've got system requirements here. Make sure you check that out because if you can't run Houdini on something like a Chromebook or a lower IN laptop or desktop, you need a decent GPU, which is a graphics card, CPU, some memory. And a combination of those things. Because again, you are, you are running a professional 3D graphics software. So, you know, it's not like running Microsoft Word or any of those kind of spreadsheets or things like that. So just make sure to check out the system requirements under support. And then we have the get. And this is where you can go ahead and download your free version. Or if you want to go ahead and buy, you know, an indie version or anything like that. So you can go to download here. And what it will make you do is it will make you go ahead and register. This is free to register. You will have a username and all that. When you do visit forums or anything like that, you'll, that'll be your username. So once you sign up, it'll go ahead and take you to the Install page and it should automatically recognize what OS you are using. So whether it's a Windows, Mac or Linux. And then you can go ahead download and then follow the standard installation process to go ahead and get that going. Okay, so that's how you can go ahead and install, download. A little bit about the side-effects website. Again, a great place to go as far as learning about Houdini and anything Houdini related, this would be the first place I would go. So please explore this website and again, make sure that you come to the get and download that free apprentice version, ok, that's the version that you want to go in and download. Okay, that's it for this video, we will see you in the next one.
3. Lesson 02: User Interface: All right, class. Welcome back. So I went ahead and downloaded and installed Houdini, and I went to have opened it up. And those of you that don't know, you get this Houdini icon. I'm running version 18.460 as of this recording. But anything version 18 and above will work for this course. So this is what it looks like. Double-click and once you open it up, you will get to this screen. So here we have a, there's pops up. You can come over here and turn this off if you want show at startup. It just kind of guides you get started learning paths. And this all will bring you back to the side-effects website for anything like that. So you can choose to show this at startup or, or just close it down. So we'll go ahead and close it down from here. So anyway, so this is what the Houdini default user interface looks like. And in this video, that's what I'm going to talk about. I'm going to go ahead and talk about the interface. In this video. There's a few things you need to know if you're coming from another 3D application like Maya or 3D Studio MAX or anything like that. This can look similar, but this also looks different because there are different components to the user interface inside of Houdini. Okay? First thing I wanna point out are the, the, the biggest thing. This middle part here is the viewport. So this is where you'll be doing all your work. This is what you'll be viewing anything. Again, if you're coming from another application, this should look similar to mine or anything else out there. So you can go ahead and rotate, tumble, zoom in, zoom out inside of this. And the way that you do that is you press the Spacebar. And then with your mouse, if you go ahead and left mouse click, you can go ahead and tumble around so you can rotate here. If you do spacebar and middle mouse click, you can go ahead and move around in 3D space here. Okay? And then if you space bar and right mouse click, you can go ahead and zoom in and zoom out. So a combination of these, if you just kind of leave your thumb on the space bar and then you can kinda toggle around and move all over the place to get a better view of your 3D scene. Okay, we'll go over some of the shortcut keys later on. But that's the basics of, of kind of moving around inside of the viewport. Okay. On the left side here you have your toolbar and I'll talk about that here in just a little bit. But you'll see all over the UI here you have these little arrows, okay, these little black arrows. And this allows you to kinda collapse these things to give you more room. If you're working on a smaller screen such as a laptop or anything like that. And give you more kinda real estate to work with inside of your, your view port here. Ok. So again, Houdini is very customizable. You can move windows around, you can set it up and customize it any way you see fit. And we'll take a look at that here in just a little bit as well. Okay. So we've got the viewport down here at the bottom is the timeline. Here. You can go ahead and play, rewind, step through frame by frame here. Ok, so by default, we have 240 frames down here. And right here is the starting frame. You can go ahead and type in a specific frame to move it there as well. You can scrub through the timeline if you want. Down here, you can come in and shorten this timeline. So maybe you don't need to see 240 frames. You can just bring this down and say I want to see a 140 frames. So there you go. You can shorten that and you can put more keyframes in here as well, or I'm sorry, frames. So if I wanted to do 500. Oh, sorry, you can't do that here. You need to come over here to the panel and you'll see this little arrow with kind of a window here. If you click that, that'll bring up your global animations options. Okay? And this allows you to set your FPS, okay, this frames per second. So by default, with film, it's 24 frames. If you get to TV, might be 30 frames. Video games or anything, virtual reality or real-time, you might be looking at 60 frames per second. So keep a look out of what actual FPS you need to use depending on what you're creating here. Okay, here's where you can go ahead and set that, that, that timeline, that frame range here. So I can start it at one. I can bring this and I can say 500 here, and I can apply. And then if you take a look at my timeline down here, you can see that now it's set from one to 500. Ok? There are some other things that we won't get to in this course. But those are the main things you're FPS and you're starting and frame range here. Okay. I'm gonna go ahead and set this back to 40. And then let's go ahead and close that. Alright. If we will go over a couple of these later on, if we get a chance. If we make our way up from the timeline up to the top right here, by default, you see this parameters window, okay? And we'll take a look at parameters and a different lesson what they do. But this is your parameters and window here. And then down here, you have your actual a network, okay, this is your node network down here. This is where we'll create things called nodes. And this is what we use to build and build out our effects or anything else. And Houdini, we use nodes. Again, we'll, we'll take a look at that in a different lesson as well. Okay, but just like anything else, if I kind of squirrel and hover over the middle here you can see I get this double arrow so I can shorten my viewport here. Same thing here with my no network or my parameters window. I can go ahead and I can collapse. If I wanted to. And then over here, each one of these windows has this little window with a drop-down box. Okay? So if I click that drop-down box, you have some different options here as well. Okay? So if I come over to say the parameters window, I can drop this down and I can tear off a pain. Okay, so if I tear this off, it'll go ahead and it'll tear off this into its separate window. Okay. If I wanna go ahead and if I want to add this back, what I can do is I can drop this down. I can close this pane tab like this. Okay. And then over here you can see my tabs. Okay, these are different tabs. We can rearrange these if we want to. You can see we get this little might be hard to see on your screen, but we get this little black line where we can insert these different, these tabs here. Okay? If we want to add a new one, there's this plus sign. So we can go ahead and click that plus sign. We can go to new pain type. And then here's our different types of panes. We can go ahead and add a new Parameters tab. And then there we go. And then I can say, okay, well maybe I went this back at the beginning again. Okay. Same thing. If I drop this down, I can close the pane, I can tear off just a copy, so I'll have one here, but then I'll have a floating one as well. Maximize the pain so it just takes up the entire screen. I can close all these pains. So if I close this like so, it'll close all those tabs. And then here we just have the network here. Okay? So this might be more useful again, if you have a smaller screen that you're working with. And we'll get again to some shortcut keys later where we can just open and close say the parameters separately. So we don't need to have a full window for that. Okay? Now if I want to get back to the default here, a couple of things I can do. I can come over to this drop-down. Okay. And I can go ahead and split my paints. I can I can split it left to right. I can split it top to bottom. So if I split top to bottom, there we go. I got two copies of each of these here. Okay. And I can come in and I can just take this and I can look at what I want to do. Okay. So I can come down here and I can move I can move that to the top. Okay? Like so if I move this up here, all right. I can also add so I can come back and add some new pain types here. So if I want to add some parameters, I can do that as well. And then just keep adding different types of pain types depending on what I need. Okay. So the easier way to get back to the default desktop here, default UI would be to come up and you see this little drop down and then it says build, okay, So if you drop this down, we have a bunch of different options here. Build, the build desktop is the standard default desktop here. Okay? So what I could do is if I click Build again, well, we're not going to see anything happen here. Ok. But if I come back and if I come back down while on the build and I come back down to reload current desktop. If I click that, it will go ahead and you can see now it's back to that default build desktop. So if I somehow messed up my user interface, I can come back and I can go to the build drop-down here and I can go to reload current desktop, okay? They have a bunch of other desktops depending on what we wanna do here, okay, if we want to animate, if I click animate, you can see it gives us different tabs and pains for working with animations. Okay? And so all these are customizable. I can put all these windows in myself, but Houdini gives us a nice way to build this stuff out without having to build out different windows. So again, if I'm more into the programming side of things, I might go to technical here. Are they good? Me a Python shell, a text port. So I can build some scripts and stuff like that. And set this out without having me to do this myself. Okay. I'm gonna go back to the build desktop here. This is going to be the, the desktop that we're going to work with in this class. So just make sure that you're at the, the bill desktop, okay? You can also customize. So say i I get rid of, you know, this appear, I just want this to tab. I bring it in like That's okay, this looks pretty good. I wanna build a custom desktop here. So if I go down, dropped down my build menu here, if I go to save current desktop as don't do save current desktop top because that can overwrite the build desktop or whatever other desktop you're on here. So you want to go to save current desktop as go ahead and do that and then you can rename it so I can say something like, you know, this is Chris's desktop. Okay? Now if I save that, it says it successfully saved to this dot desk extension here. So you can, great thing about Houdini as well is that I can take this dot desk extension and I can email this to somebody or email to myself if I'm working in a different station and load this up and have my desktop wherever I'm using Houdini. Ok, so now up here you can see it says cursors desktop and it's insides i go to build. So once I go inside build, you can see it's like, oh, did it overwrite my previous build desktop? No. All you have to do is go to build and then reload that current desktop again, and it'll go back to your build. And then here there's curses Desktop. If I come to it, there is my new desktop, okay? So it just makes it very easy to build desktops, navigate to the different desktops and all that good stuff. So one more thing I want to show you before I wrap this up. Let's go to our billed. At the very top here we have what's called our shelf tools. So these are different tools that are separated depending on what you wanna do. If you wanna create geometry, modify that geometry, create hair. Simple effects here, rigging, all that kinda good stuff you can do with a push of a button over here. And this is usually the way that you get started. And then you kind of build on from there. And they've separated this as you kinda have. You're you're building shelf tools over here. And then over here on the right you have more of your affects style shelf tools over here. So you have lights and cameras, and then you have your collision particles, fluids, pyro, cloth, all that kinda stuff where, you know, if you want to make specific types of effects, you have some shelf tools to do that over here. Ok. So the nice thing is, is that you can hover over these and you can get a little description of that. And then here you said it says press F1 for more help. So if you go ahead and hit F11, what it'll do is it'll bring up a Houdini is documentation window and it'll give you some tips how to use that shelf tool. And then you can kind of go from there and look at the documentation and stuff like that on how to use these specific tools. Okay, so that's just a quick rundown of the user interface. We're going to, we're going to take a little bit more time to look at it as we go along. But that should give you kind of a brief overview of the basics of the user interface. So again, I highly encourage you guys to play around with the user interface, see what these different tabs D rearrange things, see what these different buttons do. And, and the next lesson we're gonna go ahead and look a little bit more with the interface and then start looking at the different types of networks that are inside of Houdini and how you can navigate those as well. Okay.
4. Lesson 03: Networks: Hi everybody and welcome back. So in this next lesson here, what I wanna do is I want to start talking about the networks of Houdini. And Houdini is divided up into multiple networks depending on what you're doing inside of Houdini, okay, and this will make sense kinda as we go along. But I wanted to show you this quick, quick screenshot. If you look at where I have my, my mouse over here. And these are all the different types of, of node networks inside of Houdini. Okay? So we have what's called a scene or the object network. And that's abbreviated here, OBJ. And you'll see that inside of Houdini here in just a bit. Okay? So this is where we do kind of what's called the top level. Where our top-level nodes live, and where we'll start kinda diving inside of nodes, going inside of different networks. Again. And that sounds confusing here first, but this'll make more sense as we go along. I just want to show you these different networks. Here we have the geometry network or the service operator. This is also known as a SOP, OK, so, SOP surface operator. And you'll see a lot of these ops, OK. So there's some type of op. Sop, chop, VOP, Rob, dot, ok. Just different operators as Houdini calls them. Okay? Geometry, the surface operators where you'll do a lot of your geometry, creation and manipulation, things like that, okay? You'll do a lot of work inside of your geometry network. Okay? Materials. You'll have this Matt, which is a vector operator. We'll talk about that later on. And this is where you'll create your shaders or your textures that you'll apply to your geometry or your effects or anything like that. Then we have your motion effects or your channel operators here. This is chop. This is where you'll, you can create procedural animations and we'll talk about procedural here in just a bit. But this is where you'll kind of create animations that really don't require keyframes. Okay? And if you're used to traditional animation where you're creating keyframes, say in a 3D application. This is done through things such as noise or scripting or anything like that. Motion effects, it's very powerful. Chops is very powerful. We're not going to really get into charge, but it is there. I might make another course specifically about chops later on, because you can have a whole course on chops itself. Ok, we have Vox, which is the v_x. Operator, And this is Houdini is built and scripting language, which is called the v_x. And you can use this to customize a lot of things. A lot of your affects. Customize the way maybe your particles move around or the way that your fluid is moving or your materials look or anything like that. V_x is very, very powerful insight if you're doing a lot of things, this is a little advanced outside of this class. I probably will make a specific vex course later on, so keep a lookout for that. Here we have ramps, which is the renderer operator, okay, this is where we will be doing rendering. So anything rendering, rendering images are sequences of our effects or anything that we want that final output we're going to be doing inside of our ROP or render output here. Okay? We have the dynamics network, the DOP, OK, the dot operator or I'm sorry, the dynamics operator. This is where you can do your main effect. So this could be particles, fluids, fire, cloth, rigid bodies, anything like that. The bulk of your, your main effects work you're gonna do inside of your dynamics operator here, okay? And then last we have the COP or the compositing operator. Houdini does shipped with a built-in compositor. Okay. And compositing, if you've ever used anything like nuke. It's a, it's a professional compositing editor where you can take your rendered images and you can composite them together. You can add different compositing effects. So this is, this is something, again that's outside of this class. It is there. If you want to take a look at it, play around with it. There are documentation. It is a fairly good composite or you can do a lot with the compositor. It's not on the scale of something like nuke, but you can do a lot with it. Okay? So that's what I just kinda want to show you on this little drop-down here. And if we go back inside of Houdini, I wanna kinda just point out where and how to get to these specific networks and the specific operators. Ok? So if you come over down, let's first take a look at the, the node network down here. And again, we haven't taken a look at nodes yet. We're going to be doing that shortly. But I just want to show you this network. So if you take a look, you can see that we are currently in the OBJ or the object network, okay? And remember we saw that before. And you can see over here, it says objects. So this is where our top level nodes are elements. We start creating geometry. We'll take a look at how these networks work with one another because all these networks are intertwined with each other. They're all connected. And you'll see that here shortly. So this is the object level. And if I click this down, you can see that I can be taken to different networks depending on what I want to do. So if I want to go into the mat, this is that material builder where I can build that materials inside of this. And this is just one way I can get to these different operators. As you'll see as you progress instead of Houdini, there are multiple ways to do things inside a Houdini. So this is just one way that I can go ahead and get to these different types of networks are operators. Here we have our out. So this is where our wrapper or render output or render operator is. This is where we can do all things rendering. You can see here it says outputs here as well. Shop no longer works inside of Houdini. This used to be the old place where you can create shaders and materials and stuff that has now been superseded by the mat operator here. Okay? There's a couple of other newer ones here. We're not going to get into these in these, in this course. Here we have the channel operator. Again. This is just one way we can get inside. But you can see that a couple operators are missing here, such as the dynamics and the geometry. If I go back to the object level here, OK. One way that I can get inside of a dynamics operator, and really quick, just to show you this, I'm going to lay down a DOP network node. Again, we haven't gone over nodes yet. Don't worry about this. But if I go inside of this node, now, I'm inside the dynamics network and this is where I can do all things. Like I was talking about before. Making my fire affects my fluid effects, collision affects all that kind of good stuff I can do inside of here, okay, that's not available here at the top level, but land down specific nodes like this.net. I can go ahead and dive in and visit this dynamics network. Okay? Same thing with geometry. And we're going to look at this. If I laid down a geometry node and I dive in, we are now on the PSAP level or the geometry level here where I can do all things to create geometry or manipulate geometry inside of this, this operator here. Okay? So those are the, those are the networks or the operators that you'll, you'll hear inside of Houdini. I wanted to give you guys a quick overview of that. Again, we're going to be diving in and in the next lesson we're going to actually be creating geometry. So we're going to take a deeper look at that SOP network or that geometry network. Okay, so that's it for this lesson. We will go ahead and see you in the next one.
5. Lesson 04: Creating Geometry: Okay, welcome back class. So in this lesson, I want to talk about how we can actually create some geometry. Ok, so how we can create some geometry, there's a couple of different ways we can create it. Also how we can take a look and start manipulating that geometry inside of our SOP network or, or geometry network, however you want to say it. So let's go and get started. So first way is again through our shelf tools. And again, this is probably the easiest way to get started because allows you to get started. It has the basic building blocks. And then again, you're just kind of adding on. So if you come up to the very top, you'll have this create tap, okay? And this Create tab, you can see we can create a box, a sphere, two tours grid, and then some other kind of obscure pieces of geometry. Now, these are useful in their own different ways. Again, we're really not going to get too much into these in this course. We'll look at these, these basic shapes for now. But let's go ahead and, let's go ahead and create a sphere here. Okay, so I'm gonna go ahead and there's a couple different ways. If I go ahead and just left-click the sphere. And now if you take a look at my view port, you can see I have this kind of red cube with some coordinates on here, okay? And this is where I can go ahead and actually place this object on my grid and 3D space here. Okay, so if I go ahead and I'll just go ahead and I'm going to just click there. And then I can start moving around. Who's in that space bar and the left, middle and right mouse buttons here. And I can go ahead and tumble around our object. I can zoom in, zoom out, move back and forth, up and down. So I can really tumble around in this 3D space. Okay? So a couple of things have happened here. One, we replaced it where we've put the object. You can see that if we look at our known network, we have this sphere object one created at the object level, ok, this is at the top level here. And this is important, especially once we start getting into nodes. But I do want to emphasize that. Another thing, if you aren't familiar with 3D applications and how they worked, just a quick overview. We've put this in 3D space, and you can see that at the very middle here, it's a 00 coordinates here. Okay? And if you look over here on the left, you guys should have this by default, this is called the no min, okay? This is a 3D Newman and the three dimensions are made up of three actual axes here, ok, we have an x which is red here. So if you look at the red. It goes left and right on our ground plane here, okay? So you go left and right, which is the x axis, we get the z axes which comes towards us. So it goes back and forth. So you can see it goes out into the distance. And evil will start getting, I'm sorry, here. They all start getting negative numbers as it goes out. And then when it comes towards us here, we start getting positive numbers. Okay? So if you place it on, say one unit on the z axis, you can, you can go ahead and place that here. Okay? And then we have the y axis, which goes up and down. Well, OK, so those are your three dimensions that make up your 3D space here, where you can go ahead and place your object. Ok? So that's one way we can, we can place an object, okay, I'm going to just delete this node here. Another way, if we want to put that, put that piece of geometry right in the middle here on 00 coordinate. If I hold the Control key, so hold down the Control or Command on Mac, and then go ahead and left-click the sphere on the shelf here. You can see that it goes ahead and it creates it right there in the middle. Okay. So it just creates a right there in the middle of the 00 axes for the x, y, and z axes there. Okay, so holding Control and then clicking on a piece of geometry, we'll put it right there in the origin. Alright. So let's go ahead and get rid of that. Okay? So another way that we can create geometry is to do it through the, the node network itself. So if I come over to the node network and the object level here, and if I hit the tab key K, So the Tab key, which is the button usually above the caps locks key. So the Tab key, we get this menu, okay? And this menu is just made up of a bunch of different nodes. So there are specific categories here. So geometry and then you have specific nodes related to that. Now, each network in Houdini has its own different set of nodes. And let some kinda start wrapping your head around, is that each network has different nodes, K. Most the time, 99% of the time you're not going to find the same nodes inside different networks, you're gonna find different notes, okay? So here, if you go to primitive, theirs are different pieces of geometry. So I can go ahead and I can click, say, a box, and then I can lay a box here. And when I do it here, it automatically puts it in the 00 origin here at the center of our grid. Okay? And here's our box. Now one thing to note is that we're at the object level here at the top level. So this is an object node, okay? And one thing to look at is the, the icon here on the node. Ok? So if I hit tab, right, what we're doing is we're creating this. If we go into geometry, in this geometry node, I lay that down. You can see it says GO one and we have nothing here. Okay, and I'm just going to turn this box off real quick. We see our geo one that's displayed, but we don't see anything here. Okay, there's nothing here because this is just an empty node on the object level. So what this GO node allows us to do is I could dive into this node, okay, so again, I can double click the left mouse click or if I click on the node, see as this yellow border around it. And I can hit Enter to enter the node. And if you'd look up here, you can see that we're coming from the object level and it has this little arrow icon that now we're inside of this G1. If I wanna go back up to the object level, I can go ahead and click on this OBJ right here. Now I'm back up top to the object level. Okay, again, can dive in. And now we're inside of the geometry level. This is the PSAP level. Okay? So if I go ahead and tab, you can see that now I have a whole bunch of different nodes that make up nodes within the geometry level or the SOP, the service operator level here inside of Houdini. Okay? So again, different networks have different types of nodes depending on what we wanna do. So if we come down now to primitive, there is are different shapes or different pieces of geometry. Okay, so if I come back up, What this is is what the shelf tool is done. And if we hit tab here to primitive, what it's done, what Houdini is already done for us is created a geometry node and empty geometry note, and if we dive in, I want to turn this back on. If we dive into this node, you can see that it's laid out a box geometry node, okay? Alright, which is if I hit tab and we go to primitive, it snowed here. Okay, so that's, again, that's the nice thing about these shelf tools is that Houdini has done some of the work for us. Okay. They haven't done all the work, but they gave us the kind of building blocks, the base to kinda get us started. And this is a very simple example, but there are some more complex node examples on the, on the shelf tool. Houdini is down a little more for us, but this is just a basic example where it's laid down a geometry and then inside it's laid down a box node. Okay? So those are the two ways that we can create geometry with within Houdini. And we can go ahead and we can start creating, you know, go ahead and create a sphere from the shelf. There's our sphere. If I hide my box, you can see there's my sphere. So I can create as many nodes here is I want, we're gonna get to nodes and the next lesson. But in this lesson, I just really wanted to show you how we can actually create geometry. Now, when we create it, what happens on the object level here? How we can see different types of nodes on the object level. And then going inside. How we can see these different types of nodes inside the geometry level where our actual geometry exists. Ok, this is where we would actually manipulate this geometry and do things inside of, of, of, of this level here. Okay, so that's it for this lesson. And the next lesson we're gonna go ahead and actually look at nodes. Dive into him deeper, see how they work, as well as start looking at parameters and how those work as well. We will see in the next lesson.
6. Lesson 05: Nodes and Parameters - Part 1: Okay, welcome back class. So in this lesson, I want to go ahead and I want to talk to you about nodes themselves. Because nodes are the building block of Houdini and how Houdini works. There's a lot of benefits when using nodes. If you've ever used any other type of a program that uses nodes and node network or really what's called a procedural network. You probably are familiar with this. Nuke is one example of using a node-based system. But Houdini is used it since Houdini is going around, and especially for visual effects, it is very, very beneficial. Especially compared to somebody like, like my, again, when I'm, when I'm talking about visual effects here. Okay? So I want to kind of use our previous example in the, in the last lesson, I'm gonna go ahead and just lay down a sphere here. Okay, so I'm just gonna control, Control or Command on my keyboard and then left-click our sphere. And here, if you take a look and I'm going to just make this bigger right here. So here we have our sphere object node, okay? Remember this is at the object level here. So again, this is basically just a geometry node. And you can see in gray here, that's exactly what this is. It's a, it's a geometry node. So depending on the network that a node exists in, you'll have different characteristics to the node, okay? For example, these, this blue and this kind of greenish yellow part of the node here, these are called flags, okay? So for example, on an object nodes such as this, if you hover over this blue flag, you'd see it says display, this display. So I can toggle, left-click toggle on and off. And if you take a look over in my view port, I can hide or show the contents of this node here. Okay? So I can do it either pressing the actual blue kind of bar here on the node, or we have this kind of know, this flag ring that's around our node here when I hover over it. So I can, I can press this. And this is handy because I can zoom in and out and toggle back and forth just like I can't on the viewport. And using spacebar, left mouse button to go back and forth. Middle mouse button to do the same thing. And then right mouse button, again holding the space bar to zoom in and out. So this is handy if I have a lot of nodes and my node network here. So if I zoom out and I've got a bunch of nodes, if I hover over this node, you can see that this ring network makes it really easy if I want to show are high because I can't see the little flags on node here. Okay, so this ring network really comes in handy as far as that. Ok? So I can put as many nodes in my node network as I want. So I can control click. I can write out a box here and I can move that box over. I can move my sphere, I can just kind of orient these and you can see I get a little dotted line so I can line these up vertical or horizontal. However I want to move these around. Okay? So I'm gonna delete just by hitting the delete, selecting the node, can hit delete, so that's display. Okay, over here on this one, this is a selectable flag. So if I turn this off and now I can't select my object, I'm trying to left mouse click, select my object on the V port. I can't do that because it's selectable flag is off. If I turn that on, and now you can see I've left click and I can actually select the node. Ok? So that's an object level known in most object level nodes will look like this. There's not a lot to them. There's a display at selectable and not much else. Okay? And again, it just depends on the type of node that you've laid down. Here. You've got these little circles. And depending on, again, depending on the type of node, you could have one of these, you can have two of these, or you can have one that has almost looks like a long kind of line that sits on, thick line that sits on top of here. And these are inputs. So I can go ahead and I can feed other nodes into this node. And if I hover over this, you can see that it says parent input one, okay? Usually on object level, you're not connecting. A lot of nodes together usually do that down in geometry level. But you can connect and it'll tell you, this takes a parent node, you can connect nodes to same thing here at the bottom. This is the output of the node. So if you want this to go into another node, you can do that as well. Now, just hover over these and pay attention to what this description is saying is that'll tell you exactly what type of node can be fed into this node and what type of node can be fed out and connected to. Okay? So I want to show you an example of that right now. But let's go ahead and we're going to go into this note. And you can see again icon. This is Houdini gives us the snow. And again, this is the icon of that geometry node. Ok. Now you can create custom nodes. There's just a whole bunch of different things you can do that's outside the scope of this course. But just know that that's what this is. And if I go ahead and I'm going to just dive inside and don't worry about this right now. We'll go into that a little later. But let's go ahead and just dive in. So I'm going to double-click on this sphere one to go inside. And then there's that sphere, one node, okay? And that's what it's named here. We can rename these nodes. So if I hover over and if I double-click, you can see I can come in here and I can say something like my fear. Okay. So something like that. So I can name this however I want. If you just double-click on the label there, you can rename this. Okay. Now if you take a look at this node, you can see that we have different types of flags. This is a geometry sphere node and this is a sphere, No, because you can see in grey, it's a sphere up here. Okay. This is a sphere note and indicates with that sphere icon on the note itself. Now we have a couple more flags and different flags. So you can see that there is no selectable flag here we have the display flag. Again, I can, I can come in here. And right now, I can't turn on and off this display because I'm in the geometry level and I only have one node inside of this geometry. So it's always going to be displayed until I have another node where I can go ahead and turn that on to display. I can only display one node at a time inside of my geometry level here, okay? Inside of my PSAP level. Alright. So thats display right next to that is what's called this purple one is a template flag. And you can see that when we enable that flag and the pink one here around the ring, we had that, this pink ring around here showing the user that our template is enabled. So this is handy. I'll turn that off. I'll just go ahead and I'll start type in box. I'll hit tab to start typing box and we'll see we get a box note. And that's handy. Well, if you hit tab and you know the specific node you're looking for, if he's just start typing in the letter, it'll start narrowing down those nodes. So you can get to that specific node. Ok, so here's the box. So you can see that it's not displayed. If I put the display flag now on box, it turns my display flag off on my sphere, and now we're displaying the box. But what if I want to see where the sphere is in space here? If I'm doing something with it or I need to see it, I can turn on the template flag here. Okay? And I'm gonna just move this out so we can see this. So you can see in my example here, but now you can see that we have a little wireframe or a template of where that sphere is in space. Now were displayed and were our box is selected. But we're templating our sphere so we know where that exists, okay, and I can turn on and off, on and off this, this template as well. Okay? Alright, so that's template. If we go to the left of that, this is going to be the lock. So if I click this and I'm going to just lock it. You can see it locks the node, meaning that I can't change anything when this nodes locked, it's, it's locked into memory or temporary memory. We can't do anything. We're just we're just locking the node how it currently is right now. Okay? So you won't use that a lot of times I just wanted to show you that it's there. So just, just so you know, we can, we can unlock that. It'll say this operation will discard law changes, okay? And then it'll unlock. And then this last flag is the bypass flag, yellow flag. It turns it off here and you can see it grays out the node. And this is important when we start having a node network here. If we want to bypass a node, meaning we can bypass it, it's not used, it's not active, but the nodes still there just in case we need to come back to it later. We're testing something out or experimenting instead of deleting the node. And then maybe we do need that no later, but we forget the settings and the parameters and everything we use. We can just bypass it so it's not used, it's not active in case we need to come back to it later. Okay? So those are the four main flags onside, a geometry level node. And again, there's different flags on different nodes, but these are the main ones. So again, same thing inside of my geometry network, I can do the same thing. So I'm gonna go ahead and I'm going to delete my box. Once I do, you can see it automatically display some my sphere. So coming back to that procedural notion of nodes and how they work. And no network gets processed from the top down. Okay? So I'm going to come in and I'm going to lay down what's called a transform node. Okay, I'm gonna lay that down here. Now. Same thing, just like our object level nodes. We have input and exports here, so inputs, outputs. And if you hover over it, you can see what specific type of input that this node takes, OK. All right, so I laid down this transform. You see we get this warning sign here. And there's this arrow. And if I hover over the input, it says required to transform geometry. Okay? So what I can do is I can take that geometry, my sphere, my output. And if I click on the Output left click, you can see I get this little wire that's kind of strong onto my cursor here. And I can move this anywhere. Okay? And I can feed this now into my transform one. So it should just click right into place where once I hover over this input here on my transform, and then if I left-click, you'd see that we get this solid kind of green line here, meaning that this is the correct connection. This works. Everything is good here. Now if I put a, I'm going to take this off and I put another transform here, and I put this in here. You can see that we get this, this blue or it's not really the right one, but it's not the wrong one. Ok? And if I display this, you can see that we get an error here. And we'll look at how we can read errors here in a minute. Alright, but we get this air up and R parameters, we get this error, which we'll talk about parameters in a minute. But I just want to show you that just, if you get the wrong node inside of an, of an input, you'll usually get this warning side and to let you know that that's not the correct node to put it in there. Okay. So I'm gonna come back and my sphere. So I'm gonna put my sphere into this. And now I'm going to display my transform. And you can see that that warning sign disappeared. Okay? So what I'm doing here is I'm starting to create this node network. And this is the idea of proceduralism, okay? Where it works from the top down, meaning this node gets processed first, then we feed it, and then this transform then gets processed. So whatever changes that we have here, and if we have another node and so forth and so on. So it goes through this node chain, okay? At each node gets processed with, obviously it's different, it's different effects that it has on our geometry here. Okay? So I can move this, I can reorganize this however I want. But its processing and its coming down and process in this. One thing to remember is that as we are working through our node network, the, the bottom node, okay, if we want to turn that display flag here, meaning this is the active nodes. So it's going to process this and it's going to come down and process this. We have the display flag on. We're just displaying the sphere. Okay, we're not displaying what's happening on the transform here. We're only displaying here. Okay? So if we want this whole chain to execute, we need to go ahead and the display flag on here. Okay? So I'm gonna go ahead and just move something around my transform. I'm going to just move this in the positive direction, right here in our x-axis. So I moved that to positive X, three units. And again, we're gonna talk about parameters and stuff here in the next lesson. But you can see that now there's transform. With this transform known, I'm moved this the sphere down, three units on the x-axis. Okay? Now, if I go back and say, well, you know, I really don't like that. In an application such as Maya, I would have to do Control Z to undo, undo. And if I have a lot of operations going on, I'm gonna have to keep pressing Control Z until I get back to what I'm doing or maybe I can't get back anymore. So the nice thing about this proceduralism is that I can go to any place in my node network to check it out so I can go back to display my sphere one. You can see that it's exactly where it was from the beginning where I laid it down. So I can just bypass this all together. Ok, so I can come down. There's where I transformed it. If I want to bypass this node, I can hit the bypass ignores the transform what we did in this node, okay? And it just executes our sphere here. Okay? So that's the great thing about the bypass is I can leave the node here, I can bypass it, but if I want to bring it back later, I can bypass it to go ahead and make that note active again as part of our node network. Okay, I can also branch off. So maybe I'm like, well that's good, but I'm going to lay down another transform. And I'm going to connect that in here and display this flag. And maybe I want to move my sphere and to the positive y. So I'm gonna move this up. Okay, I'll move this up four units. Okay? So now I can start branching off and they can separate node networks here. So on that can compare, say, Well I like that, but let's go back to this display, see where this one is. So I can go and I, I'm not. If you've ever worked with Photoshop and layers, it's kinda the same thing where if you make adjustments on adjustment layers, you're not damaging the original layer. Okay, and that's the same kind of idea here, where we're making, we're make an edit, but we're not damaging the original sphere. If I want to go back, I can always go back and display my sphere. Ok, and do a new node network down here and start from scratch. Or I could build out these other ones. Or if I had something else. Maybe I'll put a mountain here. I'll feed this and I'll display that. You can see that it kinda warps my, my mesh here, my sphere. So I'm displaying that, but maybe I don't like them. I don't like that. Well, I can go back up to my transform, okay, or I can go back up here. Or I could just totally make another network. So that's the great thing about proceduralism is at it. I can always go back and I can fix things or modify or add or delete or add the new instead of being stuck just hitting Control Z going back or having to start from scratch. Okay. Okay. Or maybe I do want the mountain but I don't want it moved up to y so I can bypass my transform. So I'm processing my sphere. I'm bypassing the transform and then I'm going into my, my mountain here. Okay? So that's how these node networks and I can make, and I can zoom out and I can make these no networks as simple or as complex as I want depending on what I want to do. Okay, so that's it for this video. I'm going to kind of continue this in the next video, we'll take a look at a little more about nodes and some things that can help us organize nodes a little better. And then we'll start talking about parameters as well. Okay, we'll see you in the next one.
7. Lesson 06: Nodes and Parameters - Part 2: Alright, welcome back class. So in this lesson we're gonna go ahead and continue on where we left off and talking about nodes and parameters. I'm back up at the object level. I have my sphere that we used in the last lesson. I'm gonna go ahead and dive in Geometry Level. I deleted my other nodes that I had in here. A couple of things I want to talk about before we start talking about parameters are ways that we can organize our nodes because that's really important when it comes to no networks. Because again, you can create simple note I've, but you can create really complex node networks. So it's a good idea to be able to organize these for yourself in case you stop working on something, then he come back later on and you forget what you're doing. So you might have some notes to help you out or some other options to help you figure out where you left off or what you're doing inside your node network. Same thing if you are collaborating or working with somebody and you're handing off your project to somebody else, they will have an idea of what you were doing inside of your network. Okay? So I'm gonna come in here and I'm gonna just hit tab and I'm going to lay down another Transform node. And I'm gonna go ahead and connect my sphere to my transform, and then I'm going to turn that on. Okay? So one way, one quick thing to disconnect nodes, there's a couple of ways you can do. You can go ahead and left click and hold the note and then you can shake it. Okay? And then it'll go ahead and disconnect the node. Okay? Another way and easier way is if you hit the y ky k. So if you hold down the Y key, you'll get this little scissors icon. And then if you left-click and hold, you can see this little red line being drawn and drag it over your little wire here and let go. It'll cut that wire. And this is handy if you have multiple nodes connected, maybe you have an input. For instance, if I have this transform, I'm going to have a, I'm going to put down a merge node. And you can see this merge, it has that big thick line I was talking about in the last lesson. This means that it will accept multiple inputs. Okay? So I can go ahead and I can feed in this transform. If I laid down a box, I can put it in here, you can see, and if I laid down another one, so I can just keep adding as many nodes and ears I want. And I can just display this merge. Okay? So maybe I want to disconnect these instead of shaking each one out. I can just hold the Wai Qi left-click and drag over all my wires and let go and it will cut all those, all those wires. Okay, so just a, just a quick, quick way to do that. Alright. So how I want to organize my nodes and there's a couple ways we can do that. And if you take a look, there's a little shelf, a little toolbar up here above your node network. And over here they have some nice things to help you organize. Okay? So if you kind of skip over these first three, you'll get to these. So this first one is a color palette. So if I select that, I can select it here and you'll get this little color palette. I can toggle that on and off, or I can hit the shortcut key C. So as long as I'm hovered inside of my node network, I can hit the C key to enable and disable this as well. Okay? So maybe I'm going to select my sphere note here, and I'm gonna make this purple. So if I click purple once it's selected, you can see this is purple and maybe I have a box node here. I'm going to select it. I'm gonna make this purple as well. So maybe I wanted to say that all my geometry is purple and then all my transform here, I'm going to select, I want it to be this green color. So it's an easy way, especially when you're zoomed out, you can see that, oh, these, all these geometries are purple, this transform is green. So you can color coordinate these nodes to help you visually kind of organized and see what nodes are what inside of your network. This is very handy. Usually I'll have a, what's called a null node. And this is a node that doesn't do anything. You can see that it's a different shape as well. It's just an X. And if you look, there's really no parameters up here. And you can connect this to anything. And I usually what I do is I'll connect the end of my node network to a null, meaning that this is the end of my network. And then I can just, to label this, I'll double-click and are usually named this out an all caps. Something like this. Okay? Meaning that I can go ahead then and I can import this into another network. And I know exactly where my last note is and my network some pull in that entire network in. And usually I'll make this black. So I'll put all my nulls as black here so I know what they are. Okay? Another thing you can do instead of color, you can come over and you can see this little post-it note, okay, icon up here. If I click it, you get little sticky notes, okay? And you can make as many of these as you want. And the great thing about these is I can click it and I can make these a color over here from my color palette. So maybe I want this to be that same green as this. So here I can just click in there and say, you know, You Use this currents form to control sphere because position. Okay? So maybe I want something like that. So I know that this colour and this color match and I have a little note here indicating that and I can make as many notes and put them together with different colors. I can move these around. I can minimize this, expand it, do what I want with these little sticky. So again, this is to help me, this is to help other people figured out what's going on in your node network when it needs to be done. And another useful thing is this little box, and this is called a network box. It's next left to the Post-It note here. Okay, so I can select, say I want to select both of these. I'll just left-click and drag over my two purple transform nodes so they're both selected, you can see. And then I'm gonna go ahead and hit that little network box. So what this does is it wraps this little network box around these two nodes. And I can go, and I can just drag that network box and you can see it drags both of these nodes, okay? And I can click it, and I can select this as, say that purple as well. Okay, and then I can double-click up in the header and say geometry, something like that. So I know that, hey, these are all my geometry nodes. Maybe I have one that's my transform. And again, I can drag this whole thing around, or I can just drag one and I can drag him out if I wanted to Oregon, go ahead and drag it back in if I need to do that. Okay, so again, this is handy, not so much in this network because it's pretty simple. But you can see if I get a bunch nodes and I have a big network, it's a good idea to use these tools and these resources to help you organize your nodes so you know exactly where things are to help you, to help other people and to keep organized. Because nothing is worse than if you come into a network and these nodes are all over the place, nothing to labeled. And you have to go through one by one to kinda figure out exactly what's going on in that network. So it's always good to keep organized. Okay. Let's go ahead and move that here. If I go ahead. Another thing I want to show you is to get these, these different shapes, ok? If you look to the right of the color palette, I'm going to turn the color palette off, and I'm going to turn this shape indicator on here. Ok? So these are all the different types of shapes I can make my nodes. Ok, so maybe I don't want my transform to be this, okay? Maybe I don't want this to be something else. So maybe I want my transforms to have this shape to it. Okay, so I'm gonna click that and then you can see that now my transform has this shape. So again, it's just a easy indicator, visual indicator to see exactly o has that shape of my transform psi. Now this is a transform node, so I could go through and do that to my transform nodes if I wanted to, I could make different shapes. Just like I have here with my, my null node. I know that this x is the default for a null node, so I know exactly kind of what that is. Okay? So that's just a little bit about, about nodes, a little organizational tips about nodes and how we can keep our notes organized. That's it for this lesson. In the next lesson, I want to start talking about parameters and how we can control those and use those inside of our work here.
8. Lesson 07: Nodes and Parameters - Part 3: Okay, welcome back. So in this lesson, I'm going to go ahead and move on and talk about parameters, okay? So parameters decide nodes and networks are different depending on the network wherein in the node that we're working with, specifically the node that we're working with. Different parameters are associated with different nodes. And here again, we're just using our sphere piece of geometry. Here we're at the object level. And if I click on a, my sphere note here, if we take a look up in our parameters window, these are all the parameters that are associated with my sphere object one. Okay? So we know that because up here it says geometry. Again, this is a geometry node and here's my sphere object, one name. And then we have this transform tab, this render tab, and this miscellaneous tab. So these parameters on the object level, we have a transform order, we have a translate, and in our translate we have a X, Y, and Z channel here. Okay, So these are referred to as channels, okay? So we have an X, a, Y, and Z. So we can move these and specific increments. Same thing, we have a rotate x, y and z scale, x, y and z pivots, and a uniform scale, we can see it's just one. And then some other options down here. Okay? So that's it, the geometry level. And again, different nodes have different parameters depending on what we're going to do. Now, I never translate or do anything unless it's specified on the object level, okay, I always do that inside of the geometry level just because if you do it here, and then you go into the geometry level and make changes and transformed down there or do anything else. And you delete that down there in your objects still. Not where it was supposed to be. At the beginning. It's usually because you've translated some stuff up here on object level. So that's why I like to do it on geometry level. So I'm not doing it in two different places. That's kinda getting a little sidetracked. But so I'm going to leave this alone for now. I just want to show you that on the object level, we have some, some different parameters on our geometry node here. Then if we dive down inside and I click on my actual sphere, note here we have a new set of different set of parameters for that specific piece of geometry, okay? And these are the parameters that I want to. Mess around with as far as this piece of geometry. So if you take a look here, we've got primitive type. And if I hover over the label here, you can see that it'll tell you what exactly it does. And again, if I press F1 on the keyboard and it'll go ahead and it'll pull up some help on, on that specific node. So here's our sphere geometry node. And you can see some examples. What it actually does. Here's the parameters and what those parameters do. So you can read about those in case you don't know exactly what a specific parameter does. Okay? So here I can change and the different type of mesh this is okay. I'll just leave it at primitive. Here's the radius, so we haven't radius x, y, and z. Now i could come in here and I can just click and I could say I'm going to type in three and you can see that it widen my sphere in three units in both directions in the x-axis. Okay? Alright. Or let's just, I'll control Z. Okay? And we'll go back to our default 0.5. Or I could go ahead and I could hover over this, the x channel here, okay? And if I hover over and night, hit the middle mouse button, you can see I get this this number ladder. Okay, and that's what we call it a number ladder. And I can increment or decrement the value by a little or a lot. So I can do it by 0.0001 hour. I could do it by a 100 each time. Okay. So if I do, I can come up to one and then you can see it's highlighted. And now if I move to the right, you can see that incrementing this value by one, okay? If I go down to 0.01, you can see that increment, incrementing this in very smaller amount. Okay? So that's the great thing about this number ladder is that I can get very large amount or if I need to get real precise and make little increments, I can use this number ladder to do that as well instead of having to type a specific value, okay? And I can do this for each channel, or if I hover over the label, let's put this back to 0.5. If I hover over the label and then middle mouse, Ok, I'll get my number ladder and then I go to the right. You can see I'm doing this now in all three channels, okay? So incrementing that radius now in all three channels, okay, so if I hover over the label and middle mouse click, get my number ladder, I can affect all three channels all at once. Okay? Same thing with center. If I want to center this, I can move this center. Or I can put it over all three and move all three at once. Okay? Rotate, same thing, Uniform Scale. I only have one channel here and a slider. So I can Middle mouse use the number ladder or I can use the slider. And that'll go ahead and scale all three. And the my radius all at once. Now, this is a different parameter than this. It's not affecting this parameter. This is its own separate parameter. So I can still do this and then come in here and change these as well. Ok. Orientation. So I gotta just a bunch of different parameters on how I want to manipulate this piece of, this specific piece of geometry. So these parameters are, are located on this specific sphere here. Okay? The other nice thing is that I can come in here and I can right-click a label. So if I right-click, I have a bunch of different options and I'm not going to get into a lot of these options. But some of these, you can come in and you can copy a parameter, you can paste values, pace, expression channels, pays, relative references. I can lock a parameters. Have I locked this? You can see it's grayed out and now I can't, if I do this, it's not going to affect this. It's locked. Okay? So if I don't want anybody to mess with the certain parameter or if I don't want to come back later and mess with it, I can lock a parameter and then I can right-click it and unlock it to go ahead and modify it. Okay. Another thing, if I wanna go back to the default state of that parameter, I can right-click and I can go back to revert to defaults here, okay, revert to defaults, and that'll go back to the default value. Same thing up here, radius, I revert to defaults. It'll go back to that default value. Okay? If I want to paste, so say I want to go ahead and I want to paste this x. So I'm going to right-click, I'm going to copy parameter. So I'm going to copy this parameter. And then I'm gonna come over to the y axis or the radius here. And I'm going to just paste that about. I can paste that value. Let's change that the ten, let's copy. And then let's paste the value. And you can see I can paste that as well. Okay, so that's handy, but there's a better way. So maybe I'm going to copy this parameter. And then I'm gonna come over to this. And I'm gonna go ahead and I'm going to paste relative reference. So I'm gonna go ahead and paste. And I'm gonna do the same thing for my Z. I'm gonna paste relative and we get what's called an expression. And I'm not gonna go over really expressions in this course. Again, that's a little more advanced. But this is saying that it's going to take the channel from raid X, that's the name of this parameter k. So if I hover over radius, you can see I got parameters. Raid X-rayed, wide, rage z, k, right? X-rayed. Why raid z? So what this is doing is it's going ahead and pasting this parameter or copying this parameter pasting in here and here. And I'm pacing relative reference. So what it means is that these two channels are going to always look back at what the value is for this channel, okay? And if I click, left-click on the label itself, instead of seeing the expression will see the number. So now watch these two numbers. So if I increase this radius. This is this x. I'm not increasing the label here just on the x. If I increase this, you can see that it's increasing. And in all three and I let go, you can see each one of these has the same values as this. So it's always watching this value. And this is very, very handy when you get a little more advanced inside of Houdini. And you want to have a channel and maybe you want some other parameters to always look up at that parameter. So maybe here, I'll go back to one. I'm going to copy this parameter. And then in my center y, I'm gonna go ahead and paste relative reference. Now, automatically, this is set at one because it's looking back at this channel so you can see it's one unit off the ground. So now when I increase my one radius here, you can see that it's increasing the center y and now it's growing this off the center of our grade here. Okay? So a better example is, I'm gonna go ahead and I'm going to delete these. Chances if I right click and I'm going to say delete channels, the leak channels, and that'll go ahead and delete the channel and see it's not grain anymore, it's back to black, but we still have the relative reference here. Now if I go ahead and start increasing this, you can see when I increase my can do it on this crease the radius and X, it's also were raising up our center y here based on the value of x here. So these are linked together. Ok? So that's very, very handy, very useful in all types of situations. So I just want to show you that it's something you can do. And I can always come back right-click and I can delete the channel. And now if I move this, it's not going to affect this anymore. Okay? So I'm going to come back, revert to defaults. And let's go ahead and tab and let's lay down that transform. I'm going to put this in here. I'm going to display transform. So transform, I have a bunch of different parameters, okay? So maybe here I'm back at my defaults, but I'm going to display my transform. And now I want to translate this into why. Maybe I wanted to bring that scale, uniform scale up to say three. Ok. I can do that, but you can see that my sphere is unchanged. We haven't changed anything. We've just changed the parameters in our transform. And we change the parameters here. And I can always go back here. I can template my transform to see the different, okay, or vice versa. I could template my sphere to see where it came from and what we did to it here. Okay. And I can always come back. I can make changes. Maybe I don't want this to be a primitive, I want this to be a polygon mesh, okay? And it unlocks a couple other parameters here you can see these are grayed out. I can't do anything. But if I change this, the polygon, it'll lock these grey these out. But now I have this frequency available. Okay? So maybe I want to raise this frequency to something like 20. And you can see it added more detail to our piece of geometry here. Come down, I move this in 6.9 units. And then maybe I want to put that mountain down here. I'm going to collect my transform into here. Hit my mountain, display it, so it'll go ahead and be active. Now I can see that this mountain now has an effect on it, and this mountain node has its own parameters on here. So again, just hover over these labels to see exactly what these do. If you don't know, this doesn't give you enough, you can always hit F1 to take a look at that documentation, okay? And you can always come up to the menu here and go to Help. And you can go to the forum, you can go to examples, contents start here. And if you go to content, it'll do is it'll bring up the Houdini documentation and you can go through here and check this out. You can do a based on networks or anything else you can search. But now I have my mountain parameters and same thing, I have my ladder if I need it or I have the slider so I can start seeing what, oh, what this does. I can see, oh, look at this. You know, I can play with scale, offset, get different patterns of noise, different types of noise. So I can get a whole bunch of different cool things depending on what type of know now mountain just adds this noise and, and this deformation to our geometry here. But again, this isn't permanent. I could bypass this or I could make this active instead of this. I can look at this but then Template this to see where it was before. So I have a bunch options, but again, I can look at the different parameters here and play around with these parameters that are associated with that node, to go ahead and make changes based on that particular node and what it does. Okay, very helpful. A couple other things you get with your parameters. Over here to the, to the right. You can go ahead and you have this little question mark here. And if you click that help as well, that'll go ahead again and bring up the help for that specific node so you can read, oh, there's the mountain noted displaces points along normals based on frack a little, little more than you need to know. But if you come down, you can say how to use a mountain, what kind of parameters it is, what type of parameters are on this node? How to use them? Ok, if you come down, sorry, let's go back up to the top here. So you can look at some different things here as well. Okay? So it's just very, very helpful with the help to see what exactly what each node does and what each parameter does. Okay? So those are parameters. That's it for this lesson and the next lesson, we're going to start talking about attributes. In attributes play another vital role instead of Houdini. Will see in the next lesson.
9. Lesson 08: Attributes - Part 1: Welcome back class. So in this lesson, I want to go ahead and start talking about attributes inside of Houdini. Attributes play a very important role when it comes to Houdini. And you can do a whole bunch of attributes. When you really start working with Houdini, getting more advanced, attributes play a big role in customizing and creating some, some really, really nice visual effects. But let's talk about what an attribute actually, actually is. When I attribute a is a, is a piece of data that lives on a specific geometry or an object inside of Houdini. Okay? So we can pass attributes around, we can create new attributes, we can customize attributes, we can modify. We can do a whole bunch of attributes to control different aspects of our work inside of Houdini. Okay, so I went ahead and we're just laid down a sphere and we're instead the geometry network, the PSAP level again. And what I wanna do is I want to show you the different types of attributes, okay? So there are a few different types of attributes. There are point attributes, primitive attributes, detail attributes, and vertex attributes, okay? And the first type of attribute I want to talk about is the attribute. So if we take a look at our sphere, our sphere is made up of both primitives, which are the faces of our, of our geometry here. So it's these faces that I'm highlighting here. And those are primitives. Points are where a primitive meets another primitive. So right here would be a point. And if we haven't really discussed it, but over here on the right-hand side, we have a bunch of guides. I have some guides that work to show lights. I can lock some things I can show turn on and off my grid. You can see here, if we come down, we have some display guides, one of these being points, and it's just this little point here. If I turn that on, you can see all my points that belong to the sphere in this blue. So there are all these points that belong to the sphere. Okay? These points, they have point numbers here. You have this number 12 of the point. If I turn that on, we should be able to see the point number that's associated with this point. Ok, so I'll turn those off. But points are very important inside of Houdini. And points have their own attributes, just like primitives, they have their own app attributes, detail, vertex. They have their own attributes. Which again outside of the scope of this class. But I really want to focus on point attributes right now because in my opinion, point attributes are probably the most important types of attributes that you can create or pass around or modified or do whatever you want. To see these attributes. There's a couple different ways you can, you can visualize these attributes, okay, or to see what they're doing, what, what type of attributes you have. So one way to do it is if you come over here to your node. And if I hover over this, you can see that we have this little I icon, which stands for Information which we haven't gone over yet. So if I go ahead and click this icon, I get this popup window, okay? And this has all the information that is related to this specific sphere, one node, okay? So here I have information about where this object lives. So it's an object level and then it goes down. Okay, that's that forward slash inside of the geometry level. And here's our sphere object one here. That's the actual node, that name of the node. What type of node this is? This is a sphere. Sop, the sphere node. And then here we have some information about the object itself. Okay, so we have how many points are on this object? 266. How many primitives to 88 vertices and polygons. Polygons and prims usually coincide together. Again, these are these faces that make up our piece of geometry here. And then here we can see the center where this lives in our 3D space, the min and max bounding box. So the bounding area of this, of this particular object, and then the size of this object, that global size of this object. And then below that, we have a list of attributes, okay? And in this case it says we have 1 attribute. This capital P says three FLT and then parentheses, we have this POS. Okay? So you'll see all your attributes here, whether the point attributes, primitive attributes, detail I attributes, so forth and so on. Pretty much all pieces of geometry start and include one attribute which is this P, which stands for position. There's a position attribute. And this three, LT stands for three float, meaning it has three channels to it, an x, y, and z. Okay? And we're not going to really go over too much about the different types of attributes. We'll save that for another lesson. But just know that position is a three float, meaning there's an x and a y and a z coordinate. Okay, we can move it the position and an x, y and z position. So there's a, a position which is identified by this capital P here, okay? And I see only one. Below that you can enter a comment. So if you want another user or you say this node. You need to do something to this or there's specific instructions. By the way, this keeps going away. You can go ahead and hit this little pin and it keeps open. So now if I click anywhere this wall, we stay open here. So you can click, you can create a common here for yourself or someone else. And then here down below is the memory that this node takes up. And when it was created, last time it was modified. And then you have something here called Cook. And this is how Houdini refers to as the process time, how long it takes that node to process. So this took 1.22 milliseconds for this note took to cook or process. Ok. And the more nodes, the more no networks you have, the longer it takes that no network to process, the longer the cook times are. Especially when you start getting into dynamics, when you're making complex effects and it's taken a lot of computational power that cook time will be a lot longer. But something simple, just creating these geometry nodes are generally just modifying geometry in general, usually doesn't take a long time. Okay? But that's something to keep a look at. But the main thing we're looking at is our points and then our attributes down here. Okay, so we have that. Another way we can look at that is if we middle mouse click, this is just an pulls up that window. But for a short Amir, short amount of time as we middle mouse and hold down that middle mouse. So I can quickly say, Okay, this has 1 attribute, is 266 points. I can let go and then it disappears compared to actually clicking this and having a window open. Ok. So that's a quick way to view the attributes themselves. If we want a more detailed view of that specific attribute or the attribute on the points are primitives or anything else. If we come up here to our tabs and again, we're on the build were only using the build desktop here. But you'll have this tab over here called the geometry spreadsheet. Okay? And if I click that, we have a kind of a grid view here, an Excel style sheet. And if you look here, we have these little icons and this first one you can see these points. This stands for points. This next one is vertices. This next one I'm, it's primitives and this next one is detail. So we can view all the different types of attributes that are currently on the sphere. One, if we go to point, you can see that we have our position r, one position attribute, we have a p and then an x. Why a P, z? Because remember this is a three float as three channels associated with it. And then over on the left hand are all the points, the point numbers over here. So it starts from 0 and it goes all the way to that to 65. And remember it says we have 266 points. But because this starts at 0, not one to 65. Okay? So we can see exactly where that point is located in 3D space. So say 0.3 here is located at 0.2.1 to five and the x 0.42 on the y and negative 0.03 and the z. Okay, so you can see exactly how this works. You can drop this down and you can see a list of all our attributes. If we had more, we only have the one. So we can turn off. If we don't want to see a specific attribute, we can hide all attributes, we can show all I attributes. Or we can come over here and we can search for a specific attribute that we're looking for. Okay, now, this is really handy when we start when we have multiple attributes or we needed to see what values are associated with attributes. Maybe to make sure that that attribute is doing what it should be doing. So the geometry spreadsheet is an invaluable tool that you'll use quite often. Okay? Alright, so those are the two ways that we can look at attributes. But let's go ahead and add an attribute to this, so we have position. So let's go ahead and add a color nodes. So I'm just going to drop down a color node. Put this down here. Let's go ahead and connect it. Let's view it. And this color node adds its own set of parameters just like anything else. So there's Class. I want this to be point, I want this to be a point. Color, okay, appoint color. I can do primitive or text detail. I'm going to say point, I'll say constant and I'm gonna make this 100. So this will be red. So this is RGB, red, green, blue channels. Okay? And I can go ahead and modify that, or I can click there and I can click a specific color. But we made the sphere here red. Okay? Now, if we go ahead and I'm gonna middle mouse click this color node. And now you can see that we no longer have one attribute. We want our 2-point attributes here we have our position, but we also have this CD attribute, which stands for color inside of Houdini. So we made a point color attribute here, which is again a three float because it has an R, a G, and a B channel three. Okay? So again, we can come up to our geometry spreadsheet, and now you can see that on our point attributes we have position, but we also have color. And we can see which points have that color. So colors R, G, and B. And you can see the one here that's associated. And then if we start going down, you can see that all of our points have one on the red channel and 00 on the green and the blue here. Okay? If we want to only, I can hide all attributes and I only want to see the color channel. We can do that as well. Or if I want to show all attributes and I want to just search for color, that won't work. But if I search for cd, cd, sorry, it has to be exact. So capital C, lower case d, then you can see that we can find that attribute there. Okay? So again, this helps to identify and see exactly what this specific values are. If something's animated, if you have an animated effect in your attribute is being animated or green attribute is driven by another attribute, and so forth and so on. You can check all that kinda stuff out over here and the geometry spreadsheet. Okay, so that's just a quick, quick overview of attributes. That's it for this lesson and the next lesson we're going to kind of continue on with attributes. Look at some other types of attributes, how we can create custom attributes, and how we can pass attributes from one piece of geometry to another piece of geometry. Ok, so we'll see you in the next lesson.
10. Lesson 09: Attributes - Part 2: Alright class, welcome back. So in this lesson I want to kind of continue on with our attributes here. And take a look at how we can, how we can transfer and pass attributes from one piece of geometry to the, because that's important. When it comes to attribute sets. One of the more important things that you'll be doing with attributes as passing them, maybe from one piece of geometry to another, maybe to derive another action or to trigger something. So being able to do that is pretty important when it comes to creating visual effects. Okay, so, and, and this one, what I did is I quickly animated this sphere. If I, if I press play here, I just got it animating from 0 in the positive z axes, just straight down the z-axis here, pretty slowly, just getting animated. And it's really quite, I'm not going to go in depth into to animation. That'll probably be another course. But I want to show you is on the sphere. I just animated the center Z channel here. And you can see I have two keyframes. I started at one and I created a key frame. You can press this green key to set a key frame. And then I moved this to frame 240, set this to ten, and I set a, another key frame here. Okay, so now it'll go ahead and play an animate. And between there, another important thing is make sure you have this little clock toggle. This is the real time toggle. So this will play at the frame rate that you set. Remember we open this up and we set the FPS here. It was already at 24 hours is what I want to keep it at. So when you click this, this will play at 24 frames per second, okay? If I turn this off, you can see it plays a lot faster. The reason is, is because it's just playing as fast as your computer can process it. It's not obeying your frames per second here, okay? So what you wanna do is you want to make sure this is turned on. So this will play at 24 frames per second or 30 or whatever. You have your FPS set it. Okay. So really quick, just wanted to show you how I animated that sphere. So what I wanna do is I want to lay down a grid. So remember if I'm middle mouse click my color, I have my cd, this is my color attribute, my position attribute here. So I'm going to tab and I'm going to create a grid. Okay? So let's go ahead and let's display that grid and let's template are spheres so we know exactly where our sphere is in space. So I can align my grid so. I'm going to click my grid and I'm gonna come over here to my little selection tool bar on the left hand side. And I'm gonna click on this little no min icon down here. Okay, and this allows me to rotate in a specific axis. If I hold on to the x axis, I can rotate. I can translate. So if you see the arrows here, I can translate this in a specific direction if I grab onto an arrow of my choosing there, okay? And then I also have these arrows that are on the outskirts of the grid here. And I can go ahead and go ahead and scale and stretch that out as well. Okay. Just this Noam and I can do that or I can just select this as translate rotate scale. I can do this individually depending on what I want to do, but I'm gonna go ahead and click that. No woman. There's also the selection tool here where you can go ahead and select right now among the points. Okay, if I left-click and hold, I can select primitives, and I can just select primitives, okay? If I hit points, I can select individual points. Okay? So I'm gonna go back to my no min tool here. And I'm going to, I can stretch this out using the handle here, or I can come over to my size here as well. And I can stretch this out using the number ladder, which will stretch it out in the x or the z plane here. Otherwise, I'll stretch it out in the x plane. Okay, we can't, This is a 2D grid so we can't translate it in the y-axis up and down. So I want to put this to something like 30. And I'll move this down a little here. So if we look at our animation, you can see it covers that entire grid. Okay? And what I'm gonna do to this grid as well is I'm going to add some more rows and columns. So here's the rows and columns. The more rows and columns I add, the more detail I get to this grid, okay? So I'm going to add a 100 here and a 100 here. And you can see that now it's pretty, pretty detailed. And if you middle mouse click your grade, you can see that now we have much more primitives and points compared to what we did have. Okay? So what I wanna do is I want to transfer the red color of this sphere to the grid. Okay, so to see that first off, I want to go ahead and lay down a color node on my grid. And I'm going to make this point, and I'm gonna make this totally black as the reason I want to be black is because I want to see this red color getting transferred onto my grid. Okay? So the way I do that, and if I, if I'm middle mouse, you can see that this grid as a color and a position attribute as well to point attributes here. So I don't wanna do is I want to transfer the color from the grid to the, sorry, the color from the sphere to the grid here. Okay, so to do that, I'm going to lay down another node called an attribute transfer. Okay? So I'm gonna lay down this attribute transfer. And you can see that this node has two inputs that are required and if you hover over it, the first one says required geometry to transfer attributes to. Second one is geometry to transfer attributes from, okay? So I want to transfer attributes from our sphere. So that's gonna go when our second and I want to transfer to our grid, and that's going to come over here. Okay? And if you get the L key, why your hovered over in the node network here, the L key, it'll go ahead and organize your grids. Case there. You know, you got one here and one up here and this over here, I don't know whoever you you, you set this up. This could get messy again, especially if you have a complex network. If you go ahead and just hit the L key, it'll go ahead and organize those. Okay, So now I did that. So now if I go ahead and let's turn off the toggle. I'm gonna go ahead and keep the template on the sphere here. But you can see that now that red color is transferred to the grid. Now, we only had read on this here, but it's transferring that read to my entire grid. So if we take a look at the attribute transfer, there's some parameters up here we can mess with, ok. If you come down to this attributes, you can pass detail attributes, primitive attributes, points, vertices. If you don't specify a specific attribute, is just kinda transfer all your attributes from one to the other. Ok, so since this is a point color attribute, I'm going to turn primitive off. And over here on the points, I'm going to go to this drop down and I'm gonna go ahead and you can see the attributes that I have available to transfer. So I'm gonna go ahead and just click color and you can see it. It puts that capital C lower case d here for my color attribute. Knowing that this is the only attribute that I want to transfer over to my grid. Alright? So now I'm gonna go over here to conditions. And there are some other ways that we can control how much of this colour or this attribute transfers over to my grid. Okay? So this kernel function, this is just a specific model you can play with this if you want to get different results, I usually leave it at the default second revert to default. Same thing with the radius here and the sample counter. Usually this all at defaults here, you don't need to mess with this. The two that we want to mess with, or the distance threshold and the Blend width. So right away if it the default at Tana five-star bringing down this distance threshold, you can see that my radius is getting smaller. How much of that color I'm transferring to that grid. And the reason I added more rows and columns to migrate here is because the more detail you have, the more precise you'll get this you can see it's still a little blocky still. I'd probably want to add maybe a little more detail to my grid. But this is good for now and that's where this blend width comes in. So if I start bringing this down, maybe something like 0.2, right? And it looks pretty small, but I can take this blend width and I can start bringing this up. And you can see right when I do that, we kinda get a more of a blurred, a blurred effect from the center out. So it's not so rigid, it's still a little rigid again, like I said, I could come in. And the great thing about, again, Houdini that procedurals, I can always go to this grid and I can just add more. So maybe I want 500 by 500 and add a lot more than I can go back here and you can see that nothing's changed with the rest of my network. But this has gotten a lot cleaner, a lot smoother, and I can even bring this blend down. So something like that. Okay, so now I'm transferring, that looks pretty good. Now the great thing is, is because this is constantly transferring. If I go ahead and press play, you can see that that color will constantly transfer to that grid wherever that sphere is. Ok, so I'm transferring that color attribute only to that specific place where I'm kind of honing in that attribute on my attribute transfer. Okay? So very powerful. This is a simple example, but you could see how I can transfer this, okay? If I come back here, what I can do is I can use this attribute now to drive some other parts and my geometry. Ok? So maybe I can use that attribute to push down this geometry. Alright? Or I can make it noisy, or I can raise it up or I can have it have a specific color or anything like that. I can use this attribute on this sphere to drive some action on this grid. Okay? And we're going to look at how we can do that in our next lesson. We will see you then.
11. Lesson 10: Attributes - Part 3: Alright, class, welcome back. So I want to continue on with our lesson on attributes here. So we went ahead and we passed our red color attribute from our sphere onto our grade here. And we have that being animated along with our sphere. So let's do some, let's take that and use that to drive maybe indentation or something inside of the grid. Okay, so to do that, what I'm gonna do is I'm going to lay down a group node, ok? And more specifically, if I start typing in group, I have a bunch of these group expressions here are, I'm sorry, these group nodes. Alright? And what I wanna do is I want to use this group expression, note, okay? Now I know we haven't gone over expressions and I'm not going to go over expressions in this course. It's outside the scope of this course. But I do want to just show you a quick expression that we can use to group this. Were this attribute is being transferred to go ahead and narrow in and target the points that are being affected here by our attribute. Okay, so I'm gonna go ahead and click this. First one says required geometry to process with group expression. So let's go ahead and let's display that. Okay? So our group expressions note here, we have just a few parameters here. The first one is the type of group we want to make. We want to make a point group. So let's go ahead and change that to point. We can add as many types of groups as we want. So we can add group expressions or as Houdini calls and expressions because we use vexed, Do this. And here we can name the group. So we want to just, I'm going to call this, say red points. We can name this anything we want up here. This would be the name of our group. Okay? The next thing is that this subexpression. And here if you have a drop-down, you have some premade expressions that Houdini, Giza, or you can come in here and write one yourself. Okay? So I'm just going to create a quick expression. So remember, when we created our color here on our, on our sphere, okay? And our sphere, we gave it the 1-0-0 red. And if we look at geometry spreadsheet, I'm going to hide all of our attributes. Puts showed just the color. We have that color, red, that CD r for read on all of our points. Look at all other points. It has that one on all of our points. Okay, coming back to our group expression, what I wanna do is I want to take that red and I want to go ahead and single that out, okay, based on an expression here. So to write a quick piece of x, I'm gonna use the at symbol, okay, This is usually how you start v_x. And you have the ad and then followed by the name of the attribute. In our case, it's going to be capital C, lowercase d. So I want color, okay? Cd, k dot r for the red channel, okay. To be greater than. Alright, so that's the shift and that's the angle bracket open to the left. So greater than 0. Ok, so any color greater than 0, right here, I'm going to press Enter so 0, remember we, that we made the grid black 000. So that's all. But if there's any red, we're saying we want to group points together that have a value, a color value, specifically read that's greater than 0. Okay? So when I press Enter, you can see right away that all my points that are going to be in this red group are highlighted yellow that are affected by that. Read that color attribute. Okay, so again, just a quick little expression here to go ahead and group out those points. And if I'm middle mouse in my group, you can see that now we have 2 attributes, but we also have this point group, which we call red points. And this is how many points are inside of that group. Ok, so that's another handy thing that you can check to see your groups. What the name of your groups are if you need them, how many specific points? All that kinda stuff. Not just pointers, but primitive groups and all that kinda good stuff. Okay? So once I have that group and I can come in here, I can name that if I wanted to, I could name any of these nodes, okay? And you can see our node networks started to get bigger here. Now I can come and I can lay down a different node. Ok? So what I'm gonna do is I'm going to lay down what's called a soft transform. Okay? So I'm gonna do a soft transform. And I'm going to lay this down. And this one says points to transform. I'm going to go ahead and put my group, display this in here. And then up here, who looks familiar like a transform, No, but we also have this group here, where in most nodes have this, where we can go ahead and we can drop down and we can set a specific group that we want this node to effect, okay? And you can see we already have our red points. So if I select that, now you can see that it's only going to activate on this red points group. Okay? So here I can just go ahead and I can translate. So maybe I'm gonna go ahead and take my number and I'm going to translate that down. And you see right when I do that, I'm making an indent into the ground here. Let me turn off my grid where that point group is affected. Okay? Now the nice thing about a soft transform is that it gives us the soft radius, unlike a regular transform. So regular transform if I 0, it would look something like this where we get these hard edges. But we can go ahead and feather this out, or we get more of a blend here. So I can put that as far as I want. Ok. And now we have this little crater here. Okay? So if I go ahead and I'm going to template my sphere again up here. And I'm going to go ahead and press play. You can see that as I press Play, that this crater is moving along with my sphere and it's getting affected. Okay? So very powerful. Just by adding a few nodes, I get this effect where I have this color attribute on the sphere that's animated, that's driving another effect on my, my grid here. Ok. So really, really powerful. You can do a lot with this. And to top it all off, I get can go down and I can lay down an attribute delete. So maybe I don't want this color and all this to show up. So I'm gonna go ahead and once I'm done with my attributes, maybe I don't need them anymore. That's the final look. I can delay this attribute delete and I can delete specific types of attributes here. Okay, so there's my point. I drop this down, I can delete the color attribute. And then there we go. It'll delete that color. And if I'm middle mouse attribute, you can see that we no longer have the color attribute as part of this, okay? It exist up the ladder so you can always modify up, up the chain here. But I put this at the bottom so we don't need it anymore. It takes up memory and space. Let's go ahead and delete it so we don't need to use it. Ok. So again, very powerful. That's the end of this lesson and that's the end of this course. Hopefully, you've learned a lot in this course, how to get up and running and start with Houdini. Again, these are some of the most important aspects to learn, and we've only touched the tip of the iceberg here. So there's a lot, a lot to learn. Hopefully if you guys have learned a lot in this course, I've enjoyed teaching it and we will see you in the next one.
Chris Rasch
