Blender 5 Basics: Part 2 - Materials

1. Blender Materials: Welcome back. Aaron Ross here, once again, with part two of Blender Basics, bouncing ball. And Part two, we will look at materials and textures, also known as shaders. This is a very strong area in Blender. It's very well developed, and they've made it really easy for you to apply materials and shaders onto surfaces. I've used Blender in a professional capacity as a product visualization artist, and I want to tell you, blender really made my job a lot easier. So let's get started with materials and textures in Blender. 2. Using the exercise files: Let's take a look at the exercise files. I provided with this series of courses. You should have already done the first course at this point, and so you should have already downloaded the exercise files and extracted them. Let's take a look, once again, what's in there. We've got a folder for three D scenes. Those are the blender scenes, and they're numbered according to their course number, chapter number, and movie number. And they generally flow from one to the next. The scene file is the begin state of the current movie, and in many cases, the scene file is also the end state of the previous movie. Okay, so those are the scene files. For this course on materials, we're also going to be looking at textures or image files. There's a folder for input textures, and we can view those by icons and see there are a bunch of images in there. Some of them are high dynamic range environments, some of them are just ordinary textures. All right, go back to our project folder root. There's also a folder for output renderings. We won't get to that until the last course in the series on production rendering. 3. Previewing physically-based materials: Before we can even begin to start developing the look of our materials, we need to set up the scene environment. This is because Blender, like all three D programs nowadays, uses a physically based rendering model. That means that the materials, the lighting, and the camera all work together to simulate the way that light actually operates in the real world. And that's what makes it so easy for us to get very convincing photorealistic results. But we have to set this up in advance in order to have what you see is what you get scenario. What we're looking at in the Viewport now is a scene that has some materials set up, but is using the default environment for the material preview mode. That's up here in the upper right. We're in material preview mode. This is what we'll see by default. And this is actually not an accurate representation of our materials. And this may cause you to scratch your head a little bit. Why would the developers set up something that is not actually accurate? I don't have an answer for that. But we can easily fix it. We have to follow some steps to do so, and we'll be covering that in this chapter. But first, I want to show you the difference. This is, again, a scene that's set up with all the default parameters for material preview. Up here in the upper right, we have something that will be labeled SN, and I've named this one Scene default. This is the scene pull down, and it is very unique to blender. Normally, you have a scene file and it has a scene in it. Period. That's the end of the story. But in blender, you're allowed to have multiple scenes in each scene file. I don't recommend that. It's going to complicate your life massively. But in this special case, it will allow me to easily switch between different settings so we can see the difference. So this is the default condition of the material preview window. I'm going to go up to this pulldown list, and I'm going to choose scene finished. In this scene, I have set up all of those parameters in order to give us what you see is what you get situation. When we design a material, we will see a very faithful representation of that material in our viewport so that we will be able to make accurate art direction decisions about our materials. I can't stress this enough. This is super important. We need to set this up before we start doing any work on materials. Otherwise, we're essentially flying blind. If we switch back to scene default, everything looks dull and lifeless. There's no saturation. There's low contrast. And this is actually by design. And again, it defies all explanation, but this is the way it's set up. And it's not just blender, by the way, it's all three D programs. They all have this issue, and you will always need to take steps in order to restore your environment back to neutral. And if we switch back to scene finished, again, this is the result that we will achieve at the end of this course, and we'll be able to make accurate art direction decisions, and that will directly translate into the visual appearance that we see in our final rendering. Let's get started on adding new materials to our scene. 4. Adding new materials: Adding new materials to the scene can be done through the shader editor or from the Properties panel. The Properties panel is simpler. Let's take a look at that first. Now at the very bottom of the Properties panel currently, I see a red checkered spear. That's the material properties. If I select something such as the ball, we see the name of the object, but there's no material assigned yet. We can click on the big new button here to create a new material. And it's created with the default parameters. It's a material of the type principle BSDF. We'll talk more about what that means later. It's got a name which is just material. And at the top, we have an area for different material slots. We could potentially have multiple materials assigned to the same object and swap them out by choosing their various slots. And I don't think it's very useful. In fact, it really just complicates our lives. I don't recommend that you add more slots. Just keep one slot per object that's populated with just one material in order to preserve your sanity. I am going to rename the material, and we can call it ball after the object to which it's assigned. But we might want to give a little bit more information. Maybe we could put the word material. At the end of that, or maybe the type of material, which is, again, this principle BSDF we could call this ball BSDF. And that really gives a clear indicator of what we're dealing with. We can change the properties. We've got the base color. Click on that. It opens up a color picker, and we can use Hue saturation value or red green and blue in order to pick our colors. I can, for example, increase the saturation and maybe send this over to a different color, but we won't see any result in our viewport unless we have material preview mode enabled. And that's in the upper right here. We've got our various viewport shading modes. Material preview mode uses the EV renderer spelled EVEE and that gives us fast performance in the viewport, but also gives us a pretty good approximation of the lighting and materials. We do have the overlays still enabled from the previous course. I'm going to turn those off so we don't see these wires, go into the overlays and turn the wire frames off. Okay, so there's one material assigned. Let's assign a material to some other object like this ground plane. I can create a new material there. And I do want to immediately give it a name. And you can name your materials whatever you want. You can name it based upon the object to which it's assigned or based upon what type of material it is. In other words, what is it trying to represent? This is going to be a sidewalk material, so maybe I'll name this material sidewalk. BSDF. So again, I know exactly what I'm dealing with. And we can change that base color again, maybe go to RGB mode and set this to a solid red, red value of one, and a green and blue value of zero. And we also need a material for the backdrop. I'll select that. Click to create a new material. Immediately rename it, and I'll call it fence BSDF because it's going to have a fence texture on it. And again, change the base color so we can see that, in fact, that material is assigned. Maybe I'll give this 100% blue. So I've got three different materials. They all have absolute red, green or blue colors, 100% red, 100% green, or 100% blue. If we look closely, we'll notice that the colors don't actually correspond to those pure RGB primaries, we'll deal with that in a subsequent movie. 5. Protecting Orphan Data-blocks: Blender developed essentially in isolation, completely separated from the rest of the software industry. And as a result, Blender has many unique quirks and idiosyncrasies that don't conform to our ordinary expectations. One of those quirks is that Blender has an extremely over aggressive garbage collection policy. Garbage collection is what it sounds like. It's taking out the trash in any software program or data structure. So we want to clear out the craft or the unnecessary data, but Blender is way too aggressive about this. And specifically, if we have a material in our scene that is not assigned to any surface or object, then when we save the scene, that material will be deleted. This can be a big problem for new users. They create a material, and then they save their scene. They open their scene later, and that material is gone. It's actually been intentionally deleted. We need to protect against this because it's very, very common that we want to have a library of materials that are not necessarily currently assigned to anything. One example of that is, I often like to have a test material called an ideal diffuse material, and its purpose is to allow me to evaluate whether the lighting and camera exposure is optimal or not. That ideal diffuse material is simply a purely white material that reflects all of the light that hits it and scatters all of the light that hits it. We can easily create an ideal diffuse material. I can select the ball in the scene. And in the material properties currently, I've got a material assigned called ball BSDF. I can create a new material just by clicking on this button over here, new material. And notice that that creates a duplicate material, but it does not create another slot up here. Again, I recommend that you only have one material slot per object just to keep your sanity. And I'm going to change the name of this. I'm going to call it ideal diffuse. And I'm going to change the material type. In the surface section here, we see the surface field. This is the type of material, and it's currently something called a principled BSDF. Click on that. I want to set this to a diffuse BSDF meaning that it's not going to have any shiny highlights or reflections. I want to change the color, set that to 100% white. And the roughness, I'll set all the way up to 100%. We'll talk about roughness later. But basically, it's how shiny or glossy the surface is. It's not going to make a lot of difference in this case, but I'm just going to turn that up to its maximum of one. And now I've got an ideal diffuse material that's suitable for testing exposure. Now, if I save my scene now, the original ball material will be erased, and I will not be able to get it back because it's not currently assigned to anything. We can reassign it by going to this pulldown list. This allows us to browse the materials that are currently in the scene, and I can set that to ball, BSDF. And now the ball material will be saved in my scene, but the ideal diffuse material will not because it's not currently assigned to anything. So in order to protect your materials from being deleted, you want to click on this shield icon, and it has the extremely amusing name of fake user. Turn that on. When that's on, then whatever you're looking at, in this case, a material will not be subject to that overly aggressive garbage collection policy. And the words fake user really are extremely problematic because they don't communicate what's really happening. In blender, again, because it developed in isolation, a lot of the generic terms from computing have been hijacked and used to mean something completely different. The word user in blender doesn't mean user. In every other computer context, a user is a person who uses the software. Well, in blender, a user is some part of blender that's connected to some other part of blender. The user needs that other thing in order to operate. Okay, so in the case of a material, the object needs to have a link to the material. And in that context, the object is the user. So when we enable fake user, we're setting a placeholder. It's not a real user, but it's a user that exists really as a placeholder for a real user to prevent that thing from getting deleted when we save the scene. Now I know all of this is crazy. And again, it's just because of the unique circumstances of blenders, birth and development. It doesn't conform to many of our normal expectations. We don't expect that when we create something, it's going to get erased without ever asking us or telling us. But, in fact, in blender, that is exactly what happens. So if you want to preserve something from being erased, you enable fake user. Another term you'll commonly see in Blender is data blocks. As the name indicates, a data block is just some chunk of information. You'll also see the phrase orphan data block. That refers to some data block that does not have a user. So if we create a material and then deassign it from an object, that material doesn't have any users, and it's considered an orphan data block. And orphan data blocks will be erased when we save the scene. So this is an issue. In this case, I can go back to my ideal diffuse material and enable fake user for that as well. So now if I go back to the ball BSDF material, the ball now has this green material assigned, and the ideal diffuse material will not be erased when we save the scene, because, again, that ideal diffuse material has a so called quote fake user. 6. Viewport Material Preview in EEVEE: Material previews in Blender use the EV renderer. This is a preview renderer that's designed for real time interactivity, but it's very high quality. In fact, EV is the highest quality of any preview renderer in any major three D program, commercial or otherwise. EV is such high quality that we can even sometimes use it as the final output renderer. I want to show you how to control the viewport preview in order to get the most accurate previews so that you have a what you see is what you get situation. When you make changes to your materials, what you see in the viewport is an accurate, faithful reproduction of that material. Let's start by assigning some test materials to these objects. I've already got materials assigned to these. I want to make sure I don't lose them all. So I'm going to select the backdrop object. You can select it in the viewport or in the outliner. And in the material properties, I want to make sure that I've turned on fake user, which is the shield icon. That means this fence BSDF will not be deleted if it's not assigned to an object. I'm going to assign the ideal diffuse material I created earlier. Choose that from the brows pull down, set the backdrop to use the ideal diffuse material. Same thing with the ground. I'll select that ground, enable the fake user and assign it to ideal diffuse material. For the ball, I need a new material. I want to make a really glossy black surface that's going to reflect the environment. So I'll start by creating a new material. I'll rename it. I'll call it black, glossy. And again, enable fake user so it won't get deleted. I'll set the base color to black. And now I can see some highlights, but they're kind of blurry. We can change that by adjusting the roughness. If the roughness is low, that means it's going to be a polished glossy surface. I'll bring the roughness all the way down to zero. And now we can actually see a reflection in that surface. There's an environment in EV. It's kind of built into the renderer. There's an image file somewhere in the program files directory of blender, and that is a high dynamic range panorama. So this is a special kind of file. It's providing illumination to the scene. And it's able to do that based upon two things. Number one, it's an all over environment. It's the entire environment, 360 degrees around and 180 degrees from top to bottom. That's known as a spherical environment or an equirectangular projection. It's the entire environment stored in a single file. And additionally, that file is a high dynamic range image. That means it can store all of the possible brightnesses that the human eye can even see so that means it can actually store the brightness of the sun or if anything. That allows that image to actually project light into the scene. Very cool stuff. So we've got this environment that's built into E V, and we can access that if we go to the material preview options. We have a pull down list on the very far right. And we see that same image here. That's a preview of this environment. We see it here in the reflections, and we see it here in this test sphere. If we click on that, then we can choose some other built in image that's going to provide illumination to the scene with this high dynamic range format. So if we choose one of these other images, we get a different reflection, and we get different lighting, different color. If I choose this one here that's a green field, that's a pretty clear example. The backdrop object is rendering as slightly green, and the ground object is rendering as slightly blue because the ground is mostly capturing light from the blue sky, and the backdrop is mostly capturing light from the green field. So this just tells us that any color that's inherent in that high dynamic range image is going to affect the scene. Well, when we're testing materials, we actually don't want color in our environment. If we go back up here, we can choose this one, which is a studio lighting setup, and it is neutral. There's no color in that, but it's actually not suitable for testing our materials because most of the environment is solid black. So we don't get much in the way of reflections here. This doesn't give us a good impression of what our highly polished material actually looks like. So, in fact, none of these are actually suitable. We're never going to use any of these. We need to use something that we can control. We'll look at assigning a custom environment to the world in the following movie. 7. Setting up a World Environment: In the previous movie, we saw that the EV material preview mode has an environment inherent in it, and we can choose among different environments. We can go back up to the material preview shading options, and we can click on the environment sphere and choose a different environment there. But unfortunately, none of these are actually suitable for proper material testing. To test materials, we want an environment that is both completely monochrome or color neutral and also has detail in the environment, so we can see reflections. Well, none of these satisfy both of these conditions. We do have one that is neutral lighting, the studio lighting setup, but it doesn't really have any environment, and so we don't really see much in the way of reflections. We need to supply our own high dynamic range image, and I provided that with the exercise files. We want to go into those viewport shading options and enable the checkbox that says seen world. When we turn that on, the lighting in our viewport is now derived from the actual scene file and not from the blender program files images. Again, we have some stock images that are provided with Blender, and those are in a way, kind of built into EV. We need to enable SN world in order to properly supply our own high dynamic range image in the environment. You'll also see scene lights. Turning that on and off has no effect right now because there are no lights in the scene. But if I did have lights in the scene and I wanted to see their effect in material preview mode, I would need to enable scene lights. Our next step is just to evaluate what's going on in our viewport. If we dolly back with Control middle mouse, we see something kind of strange. We do have our black sphere, but now our backdrop and our ground plane are nearly or completely invisible because they're exactly matching the color of the background. That's happening because that backdrop object and the ground plane object have an ideal diffuse material assigned. We can see that in the material properties. This ideal diffuse material reflects 100% of the light that hits it and it scatters that light. So the color of the object is going to be exactly the same as the color of the environment if the environment is just a flat color, which is the case. The default world in blender is a neutral gray, flat color. You want to go into the world properties. Looks like a globe. Click on that. And in blender terminology, the world is synonymous with the environment. The environment is an invisible sphere that surrounds our scene. And we see it's labeled as a surface here, but that's technically not accurate. A surface is really something that can accept light. This is not something that can accept light. We can't shine a light onto this. So it's not actually a surface. It's an invisible sphere that surrounds our universe. And by default, it's just a neutral gray color. If I click on that color swatch, I can, for example, increase the red component, and now I'm flooding the world with red light. Okay, I don't actually want to do that. I want to assign some image to this color. And I provided that with the exercise files. If we click on the dot to the immediate left of that color swatch, that will allow us to browse for some image or map or texture that's going to be applied to this color. Click on that dot to the left of the color swatch, and we get a pop up. We need to choose what we're going to assign to this color. And in this case, it's an environment texture. Click on that. Now our viewport turns into this really hot pink or magenta color. And in blender, that's an indicator that there's no map or no file assigned. That's an indicator that there's something missing. So when you see your objects render in this hot pink or magenta, that means that the link to whatever texture file is not working. Well, it's not working now because there is no link yet. We haven't actually established a link. We want to go back over to our world properties and click on Open to browse. We want to navigate to our current projects Textures folder, wherever that may be. And in this case, I've placed it one level up from the Scenes folder. I'm currently in the three D Scenes folder. I want to go up one level. Now I'm at my project root. And actually, while I'm here, I'm going to add a bookmark. Click on that, so I'll always be able to easily get back to this. Then I'll go into input textures, and there are a bunch of files in here. If I choose ENV modern buildings dot HDR and click Open Image. Now I've got a high dynamic range image in my background. And if I orbit around with middle mouse, we can see that it's a photograph, but it's a photograph that encompasses the entire environment in every direction. This is the color version of this image. I downloaded that from a website called plyhaven.com. They have many free resources, including many high dynamic range panoramas. But, again, I want this to be neutral. I don't want it to actually color my scene. So I created a version of this where I desaturated all the color. I took this image into Photoshop and I removed all saturation, and then I saved it back out without changing the actual type of file. This is important. This is a high dynamic range image. It's a special type of image. It's not like an ordinary JPEG, which is a standard dynamic range. So I made certain that when I saved out, I did not change the color mode or the bit depth of the file in Photoshop. I just removed saturation. So I've got another file for that. Click to browse, and it's called ENV Modern Buildings k monochrome dot HDR. Click Open Image. And now that is a black and white image that's not actually providing any color, but it is providing a very detailed environment that we can see very clearly in this glossy black reflection. Alright, very cool. That is how to assign a high dynamic range environment to the world. 8. Correcting Color Management: We're almost at a place where we can make accurate decisions on art directing materials. We're almost at a place where what we see in our viewport is what we're actually getting in our material. And we're not quite there yet because there's a couple other things we need to deal with. Most importantly, color management. Color management is a system whereby we can control colors. If you're used to two D graphic design or photography, you might be familiar with the idea of ICC profiles, where a document may have some associated color profile that allows it to faithfully reproduce colors on a particular device such as a printer or a monitor. So in three D CGI, we've got a similar system OCIO, which is the open color input output standard. So when we have a three D scene, we can actually represent any possible lighting intensity in that three D scene, and that can be measured in exposure values, and they correspond to F stops on a camera. So we can represent up to 20 stops of latitude. And that means we can represent any possible light intensity that the human eye can even see, which is fantastic. But what the designers of all the three D programs have done is they've set this up so that those 20 stops of exposure that cannot be represented on a monitor or printed on a page, those 20 stops have been crammed into a limited standard dynamic range that can be displayed on a monitor, and that is a bad thing because it actually distorts all of our colors. So let's investigate this. I'm going to go back to my backdrop object. Back to the material properties, I'm going to reassign the fence material, and that's a solid blue. I'll select my ground plane, and I'll reassign the sidewalk material. And that's a solid red. We can see that this color here does not correspond to the color in the viewport. I'll back out with Control middle mouse. And that's partly due to the fact that we've got some shiny highlights here. I can disable those highlights by setting this IOR or index of a fraction to a value of one. We'll talk more about what IOR means later. But basically, now we have an ideal diffuse material that is solid red, but it's not rendering a solid red in our viewport. So we're not getting what you see is what you get. We can't make accurate art direction decisions because we are just operating in a completely uncalibrated environment. Okay, so our next step is we need to go into color management, and that's going to be in the render properties. Looks like an old school television, L on that. And you need to scroll way down to the very bottom. This is a super critical setting. It really determines the color of all of your renderings, but it's buried way down here in the bottom. We need to open that up, okay? And we have the display, which is set to SRGB. That's what we want. Your computer monitor is using the SRGB color space. So display is what we want. Look, it's set to none, which means it's not actually making any changes to the lighting. If we set this to something else, we'll see, for example, we can get a really high contrast shot. That's something that you want to control in post production, not at render time. So we do want the look to be set to none. Also have exposure controls in here, and this is just like the exposure on a camera, except it works in whole numbers. If we bring the exposure up by one integer, that's going to double the amount of light coming in. Well, if we crank this exposure up enough, it'll blast out. Okay, so we want to set this back to its default of zero, meaning there's no change made to the exposure. The setting that we really care about here is the view transform. It's labeled view, and it's set to apply this tone mapping profile called AGX. This is really, really important. We want to set this to standard. Nothing else. No other setting. The only setting that actually tells us what our material actually looks like, and the only setting that's going to give us control over our lighting and rendering. Is standard, which actually means no view transform. And that's what we want. We don't want our colors to get mangled. So I can't stress this enough. You need to do this in every single scene. It's not the default. So I do recommend that you create a template scene with the view transform set to standard. And to refresh your memory, if you go into the file menu to default, you can save a startup file. I'm not going to do that now because it would save a startup file that includes all this geometry and this world and everything else. Okay, so our color management is now finally sorted out. If we go back to selecting this ground plane, for example, and back to the material properties, we want to go back up to the top here, scroll back up. I've got this base color. If I hover my mouse over that, we get a larger preview, and we can see that it's solid red, and we're getting solid red in our viewport. What we see is what we get. Okay, so back to our sphere. I want to zoom in on that with Control Middle mouse. And I want to assign that to the ideal diffuse material we created earlier, because that's going to allow me to see if there are any issues with the brightness of my environment. And there are some issues. With color management set to no transform, the view setting set to standard. Now, we can see that this sphere is actually overexposed. And if I orbit around with middle mouse, we can see there's this gradient here, and everything beyond that gradient is blasted out to pure white. That's telling me that my environment is too intense or too bright. And in fact, if we control middle mouse dolly out, we can see that in the environment itself. It's overexposed. And it was overexposed previously, but the color management setting was masking that fact. Again, it was cramming all the possible brightness values into a limited range. Okay, so this is telling me my environment is overexposed. That in turn tells me I want to go back to my world properties and reduce the strength. And I don't know how much I need to reduce that strength. So I want to go back to seeing my sphere very large. I can control middle mouse drag on there. So I can see the entire sphere. I can see all the brightness values from the brightest point to the darkest point, and then I can adjust my strength so that we're not getting any clipping or distortion. And in this scene, it looks like a value of maybe 0.5. Actually a little bit lower. Let's give it 0.4. And so now I'm not getting any really dreadful hot spots, except maybe a little bit there. I'm gonna bring that down even more. 0.3. Okay. So now I'm not seeing any hotspots, maybe a little bit more, 0.35. I just got to dial that in until I'm not seeing any distortion. And it might be difficult to see. Maybe it takes a trained eye to see that, but now I've got this dialed in so that my shot is not overexposed and it's not underexposed. I've set the brightness of my environment correctly. I've got correct color management settings, and now I can actually make accurate decisions going forward to design my materials. 9. Physically-based material properties: Now that we've got our environment set up for accurate material previews for look development of materials, we can start to investigate the base properties of a physically based material. I'll select the ball object, go to the material properties. I'm going to reassign the ball BSDF material. Let's start to talk about the surface type we're seeing here. It's of the type principled BSDF. And if we click on that, as we saw previously, there are a lot of other shaders or materials from which to choose. Many of them have the letters BSDF after them. Those are all components of this Uber shader or this meta shader, which is the principle BSDF. You might want to use one of those separate components if you've got a very simple material. But the principled BSDF being the Uber shader is going to be the most versatile, and you're going to use that most of the time. The word principled means that it follows the principles of physically based rendering. And basically, all renderers today are physically based on some level. They have different levels of fidelity to the real world. The EV renderer in the viewport does not support bounce light, so we can't have light bounce off one surface and illuminate a nearby surface. For that, you would need to use the cycles offline renderer. BSDF is an acronym standing for bidirectional scattering distribution function. It's simply the algorithm that calculates the way light bounces off of the surface. We saw the base color previously. That's pretty self explanatory. That's the dominant color of the material. I'll click on that. And for the purposes of illustration, I'm going to bring that down to black. It's going to give us a better sense of what roughness does. Roughness is the second most important parameter here. It determines whether the surface is glossy, shiny, and highly polished, or whether it has microscale deviations in its surface that give it a rough appearance that scatters the light. With a default roughness of 0.5, we have some broad highlights. If we bring the roughness down, those highlights will start to come into focus until eventually, with a roughness of zero, we have a perfectly polished surface, almost like a mirror, but not a mirror because a mirror is going to reflect all of the light equally. And here we see that it's not reflecting the same across that surface. It's reflecting hotter or more intense reflections on the edges and less intense reflections where the surface is pointed towards our point of view. And again, that's physically accurate. That's the way that real materials work. If we bring the roughness up to its maximum of one, we get a very diffuse or matte finished surface. It still has highlights, though. We can see that it's a little bit brighter here than it is over here because the light is coming from this direction. So even though we have a base color of absolutely black, it's not rendering as absolutely black. And again, that is physically accurate because a rough surface in the real world, even if it has a totally black surface, it's going to scatter light. So that's the way things actually really work. Okay, so I'm going to bring that roughness down to zero again because I next want to illustrate the metallic parameter. Metallic will fade between a non metal material shader and a metal material shader. And there are two different material shaders because metals operate differently from other types of materials. We'll only see this if we bring our base color up to a non black value. So I'm going to bring it all the way up to white. But here's a non metallic surface. It's like a shiny plastic or maybe a billiard ball. It's very highly polished, we can see that it has reflections, but it also has a high albedo or a high diffuse reflectivity. But if we bring the metallic parameter up, we'll start to see reflections dominate. And with a metallic value of one, essentially, we've got a ball made of chrome or silver or stainless steel or aluminum, a non colored metal. And that means it's going to reflect its environment equally in all directions. If we wanted colored metal, then of course, we would change the base color, and we could make it gold or copper or whatever we wanted. Okay, so I'm going to bring that back down to black. And bring my metallic back down to zero because I also want to talk about IOR or index of refraction. And that's a real world metric that measures the density of a material. A more dense material is going to reflect its environment more strongly, and a more dense material is also going to bend light as it travels through a transparent material. So the default IOR or index of refraction is 1.5, which corresponds to ordinary window glass. And we're not seeing any refractions here because it's not a transparent material. It's an opaque material. But IOR also affects the reflections. If we reduce the IOR, if we bring that down, then we're going to see less intense reflections. Let's say I set my IOR to 1.2. We still have intense hot reflections on the edges of that surface where the surface is basically aligned with our line of sight. We've got a line of sight going into this view, and the surface in the center of the sphere here is at right angles to the line of sight. The surface on the edge of the sphere is parallel to the line of sight. So this is a material that's not very dense, and so the reflectivity is most intense on the edges. If we bring the IOR up, then we're going to actually achieve a metallic effect. Now, the real world metrics here range from one, which is air to 2.3, which is diamond. And if I bring IOR down to one, then we get no reflections. This is as if it was a material that has a density of zero. So that's one way that you can just turn off the highlights or reflections on a surface. It's just said it's IOR to one. And we are allowed to bring this up beyond the density of real world materials. And if we bring that up to a value of ten or something, it's actually going to be hotter than really possible, a metal that's beyond metal. And that might be useful if you want to do motion graphics with super highly reflective logos or something like that. But for photorealistic renderings, we want an IOR that ranges between one and about 2.3. I'll set this back to its default of 1.5. For a ball, I want to have a non black base color, and we'll map this color later, but I'm just going to set this to a neutral gray, and I want some amount of roughness. It's going to be a plastic ball, so it's going to be pretty shiny, pretty highly polished or glossy, but not a perfect mirror. So I'll bring that roughness up to, let's say, 0.15. And now I do have some reflections there, but they're kind of blurry. Alright, so those are the most important parameters of a physically based material. 10. Working with nodes in the Shader Editor: Previously, we saw how to start building out a material or shader network by adding something to a material. That's known as a node. It's some part of a material. To refresh your memory, what we did was we went into the world properties and we added an environment texture to the world. And the process there was to click on the little dot to the immediate left of a color swatch. And that allowed us to add an environment texture and then subsequently browse for that file on disk. So we could build a Shader network or a material definition from this material properties panel, but that's only going to be effective in a really trivial case, such as we saw with that world Shader network. A real Shader network is going to have more complexity to it. It's going to have more moving parts. You want to be able to see all those parts at once. You want to be able to make and break connections really easily, and you want to be able to select any part of that Shader network and immediately access its parameters. The way to do all that is through the Shader Editor. It's a separate window that's dedicated simply to designing shader networks or material definitions. We can get to that from the shading workspace. If we click on shading, it opens up the Shader Editor down here. But it does a bunch of other stuff that I don't actually want. It opens up a browser. I don't need that because I've already got a browser in my operating system. It opens up an image viewer. I don't need that either. It opens up a viewport that's set to material preview mode, but it's not the settings that I have in my world, and it's not the actual framing that I've established. This is actually not helpful. It has undone much of the work that I've meticulously undertaken to set up my environment for accurate material previews. So I'm not going to use that shading workspace, and I actually don't recommend that you use it either. I'm going to stay in the layout workspace and open the shader editor in a floating window. I can go to the Window menu and choose new window. Within that new window on the upper left, I'm going to choose the editor type, and that's going to be the shader editor. We're in the default context, which is object up here. So we're going to see the Shader network for the selected object or the most recently selected object. If I select the backdrop in my viewport, I see its Shader network. We see it's a principled BSDF with a base color of blue. We can navigate in here with a middle mouse button. We can zoom in and out with Control Middle mouse. The Shader network also has a side bar up here, which is sometimes useful, but we don't actually need it most of the time because all of the parameters for materials and texture nodes are going to be found directly on those nodes. This is an extremely helpful part of blender. They made it really easy for us to quickly and efficiently set up a Shader network. We don't need a separate property panel in order to do that. I don't need that sidebar, so I can hide it using the key on the keyboard. So again, I'm in object context. If I select an object, I'll see its shading network. There's also up here different context. We can choose the world. And now we're seeing the Shader network for the world that we created in a previous movie. And it's a very simple Shader network. It's just got three nodes. And the flow goes from left to right. So a node is going to flow into a node directly to the right of it. The outputs are on the right, and the inputs are on the left. These things are color coded. Green indicates a shader output. Yellow indicates an RGB color, and these are different data types. That's a basic overview of the shader editor. Going to go back to object context, and in the next movie, we'll start to build out a Shader network for an object material. 11. Adding Image Textures: Now we're ready to start building out a simple shading network for an object material. I've got my shader editor open, and I've selected the backdrop object so I can see its shading network. We see the name of the material listed up here. It's currently fence BSDF. So we just want to connect something to this base color, and I've got a fence texture already stored on disk. I've provided that with the exercise files. We need a new node here, which is an image texture. We can add that by going to the menus in the Shader Editor. We can choose ad. Look through the categories here, and we can see under texture, there's an image texture. If we click on that, then that node is created and we're dropped into a move tool. We need to position that node somewhere and then click and that'll actually finish the creation process. I'll navigate with the middle mouse button push that over to the side. I want to position this image texture, and I want to connect the RGB color output of the image texture to the base color input of that principled BSDF shader or material. Now, in my viewport, the object turns black because I've not assigned a texture file yet. To create a link to a texture file, I want to click on the button labeled open and then browse. We previously saw that our current directory where three D scenes is stored is here, and we want to go to the image Textures folder for this project. And I previously created a bookmark for that, so I can click on that. Or you can just go up one level to the parent directory. Now we're at the root level of our project. And then the input Textures folder is where the source images are stored. Go in there, and we want to choose the file wood planks weathered base dot png, base meaning the base color. Just like that and click Open Image. And that image is now loaded into this texture node, and we see there's an image applied onto the surface. Cool. So we haven't dealt with the placement of that image. We'll look at that in the next movie. But we got an image there. Let's do that for the ground plane as well. Select that ground plane, and this is the sidewalk BSDF material. And once again, we want to connect an image texture to the base color. We can also do that by just dragging out from the input to that base color. Just click and hold the mouse button down on that base color input port and then drag out when you release the mouse, you'll get a pop up window with a list of possible nodes that you could connect here. And anything that you've recently created is going to be at the top of that list. So in this case, I could just click on Image texture. But for the sake of argument, let's say, I don't have image texture at the top of the list. I can search for it. I need to know the name of it. I could also scroll through this long list, but basically, you want to know the name of what you're looking for. I can type in TEXT, and I see a lot of hits here. These are all the various types of textures. The one I want is an image texture, which in blender means a file texture, some image that's on disk. The rest of these are all so called procedural textures, and they're generated by algorithms within blender. I'll click on Image texture. The node is created, and once again, I'm dropped into a move tool. And if I move my mouse without clicking and dragging, I can position that newly created node. When I have it where I want it, I can click the mouse button, and that completes the operation. The image texture node is created and automatically connected to the base color. Once again, I'll need to browse. Click on the open button. And once again, I'll need to browse to my current projects image files where I've got my source images. And again, I can click on the parent directory, go up one level from the scenes folder, and I can go down into input textures. And because I'm probably going to want to go in here a lot, I'm going to click on the plus sign here to create another bookmark there. And in this case, we want to choose the sidewalk base color, sidewalkbs dot png, and click Open Image. Now we've got an image applied there. Again, a very simple Shader network. We can minimize or close the shader editor, navigate around in the viewport with Middle Mouse, and we can see that we've applied a couple of textures there. In the following movie, we'll see how to assign mapping coordinates within the Shader network in order to position and scale those textures properly on those surfaces. 12. Adjusting mapping coordinates: We've applied image textures onto a couple of the surfaces. We now need to control the placement of those textures on those surfaces. Let's look at this from the top you. That's going to give us a clear indicator. We're seeing the ground plane here in the top orthographic view. Let's dolly out a little bit, Control middle mouse and position this with shift middle mouse, because I want to compare that ground plane object to the original texture file that's applied to it. I need another window for that. Go to the Window menu, new window on the upper left, choose the editor type image editor. And then go to the image menu and choose open. Go to the current projects Textures folder, input textures, and the file is sidewalk based dot PNG. Open that up. Zoom out, control middle mouse, make that a lot smaller and also make the window smaller. We want to do a side by side comparison of the original image file versus what we get in our actual object, the placement of the texture on the object. We want to size these up so they are approximately the same. And we can see that they're not the same proportion. The tiles on the sidewalk on the actual image file are mostly square. But on our ground plane object, the tiles are much wider than they are tall. That's happening because the UV coordinates for a primitive such as this non destructive plane are set up so that they're going to stretch across the entire surface of the object. The texture just gets stretched to fill the available area. And if the aspect ratio or proportions of the plane don't match that of the texture file, then we're going to get some stretching and distortion. We can correct that by just changing the proportions of the object itself. If I select that ground plane, go to the modifier properties, I can adjust size X or size Y and get that into the same proportion. And in fact, if I put in a value of 2.67 for size Y, I would have the same aspect ratio. Now, the object has an aspect ratio of 1.5, which matches that of the chekre file. But this is not a good solution because we've changed our layout. I want size Y to be 2 meters and to set that back. We need to be able to control the size, proportion, and placement of a texture independently of the proportions of the object itself. To do that, we'll go into the shader editor. I've got that minimized. Bring that back, and I've set it up so that it's just taking up the bottom half of my screen here. Here is the Shader network for the sidewalk BSDF material. And we've got an image texture here. We want to supply new mapping coordinates. That means we want to plug a mapping node into this vector input. A vector data type has three values. We're only using two of those. We're using the U and V U is the width of an image, and V is the height of an image. And each point on a polygon mesh object has got U and V coordinates that correspond to some point on the actual texture file. We're going to supply new UV coordinates. Or more precisely, we're going to take the UV coordinates that are already on the object and stretch them and position them to get the result we want. We'll need to connect a mapping node to this vector input. Click and drag on that, release the mouse and do a search for mapping and then choose the mapping node. Position that node and click to complete the operation. We can navigate with control in middle mouse, zoom in and out, middle mouse to position. So the mapping node is actually erasing the UVs. Mapping is there to transform something, to change some values, but we're not supplying any values. And so the result is we've actually erased the UVs in the shading network. We also need to grab the UVs from the scene. On the mapping node, we've got multiple inputs. We're concerned with the vector input. Click and Drag on that vector input and then drag out and release the mouse. We do another search. We're looking for texture coordinate, and we can type in CORD. We see multiple entries for texture coordinate. These are all the various outputs of the texture coordinate node. If we choose one of these, that output will be automatically connected. And that's we want the UVs to be automatically connected. So I'll click on texture coordinate UV, position that node, and click to complete the operation. Now we're back to zero. We're back to where we were when we started. We have the UVs that are on the object. They're going through this transform mapping node that's not doing anything to the information, and then that's getting passed to the texture node. Okay, so we want to make some changes to the scale and location. And I've already investigated this. I already have done the math. I want to change the scale X or Y. If we click and drag on scale Y, we see that we're stretching and basically, I want to take the original image file aspect ratio and then divide it by the aspect ratio of the plane object or the grid object. The original file has an aspect of 1.5. Is height is one and its width is 1.5. The object itself has an aspect of two. The height is one, and then the width is two. So I want to take 1.5, divide it by two. That gives me a value of 0.75. That's the scale factor here. Put in 0.75. Now the proportions are correct. And if we dolly out a little bit here, control and middle mouse, we can see that the shape of those squares is the same. The height is not the same, though. So we can see if we position this again with shift and middle mouse, the height of this object, compared to the image here is not the same. Again, they have different aspect ratios. So in order to analyze this and more clearly see what's going on, I'm going to position these over one another because the constant here is going to be our width. So that's the X dimension. And again, I'm just going to position these. Okay, so now we can see a little bit more clearly that the aspect ratio of these squares is the same, and now we just want to change the position. And that is the Y position here. And if I drag my mouse across that, we're seeing we're shifting that image on the surface. And the value I want for this is 0.25 because I basically want the image to be larger than the available area of this object in this particular case. And so I've basically got what I want now. I've set the scale and I've set the position. So we're basically where we want to be. Cool. So that's all we need to do. In this particular case, I can close or minimize these windows, and I can middle mouse drag and go back to a three D perspective. I can shift middle mouse to change my position and control middle mouse to zoom back in. I've dealt with my ground plane, and in the next movie, we'll look at combining this image file with another image file in order to give the illusion of relief or a bump map. 13. Bump mapping: We've seen how to apply a color map to vary the base color of a material. Now let's look at a bump map, which is a type of relief map. The purpose of a relief map is to deviate a surface so that it has some large scale bumpy texture to it. And a bump map doesn't actually change the underlying geometry. It's just a lighting effect that's going to give the impression of a bumpy rough surface. This will be really easy to see if we do this on the backdrop object first. I'll select that. And we've got the shading network, which is the fence BSDF, and it's got a color map applied to it. We want to now connect something to the normal input of the material. Now the word normal in CGI has many meanings. In this case, it's referring to something called the shading normal. Every pixel in a rendered image, including this viewport, is going to point at some surface. And where our line of sight or where that pixel intersects with that surface, the renderer is going to test the orientation of that surface in order to determine the lighting, and that's known as the shading normal. What we want to do with a bump map is to deviate that shading normal so that at that location, the surface is going to be point in a different direction. And that's going to give the illusion of a very large scale, rough, bumpy surface. So that's why we need to connect to the so called normal input. So we'll click on normal and drag out, release the mouse, and we want to connect a bump node. So we can type that in and then click bump, position that node and click to complete that operation. But we haven't connected any image yet. There's no texture connected to this, and we'll need to connect to the height input. It'll be easiest to see this if there's no color map. So I'm going to just briefly disconnect the base color texture and set the base color to white by reducing its saturation down to zero. Now connect something to this height input, click and drag on that, release the mouse, and it's just going to be image texture. You can search for that if it's not showing up. We want to connect to the color output of the image texture. And again, position that and click to complete the operation. We can zoom in our view port and get really close. This will be easier to see. We want to browse for our image texture, click Open and as always navigate to the current projects Textures folder, which is input textures, in this case, and select the file texture, and that is wood planks weathered bump dot PNG. And click Open. And we can see now that there's a bump map applied. We can exaggerate that by increasing the strength amount. So in the bump node, I'll increase the strength up to a factor of ten. Now, it's really clear that we've got a bumpy fence texture. I'll reconnect the color image texture to the base color of the material. And now we've got a nice material that's got both a color and a bump map. But I do want to control the size and placement of those textures just as we saw in the previous movie. So I'll back out here, and I'll just grab the nodes that I created on the other objects material and copy those over. Select the ground plane. I want to select the texture coordinate node, shift, select the mapping node, copy those with Control C, go back to the backdrop object, and then Control V to paste those in. And let's set these values to neutral before we connect anything. We'll set the Y location to zero and the Y scale to one. So now this mapping node is just passing the existing texture coordinates through transparently. We'll connect that mapping nodes vector output to the vector input of the color texture, and also to the vector input of the bump texture. So now that mapping is feeding both the textures, and so they will remain aligned with one another as I change these mapping coordinate values. All I really want to do here is adjust the scale. I can set the scale X to a value of two, and that's going to cause the texture to tile twice in the X direction or it's actually the U dimension of the texture. Cool. So now that's actually just exactly what I want. I can also add a bump map to the ground. That'll enhance its realism. I can select this bump node, select that and also select the image texture node. Shift click on that and copy Control C, go back to the ground plane and Control V to paste. Move those around. We just want to connect the bump normal output to the materials normal input. And we also want to connect the vector output of this mapping node to the vector input of the bump texture node. And then finally, we want to browse just as before, and we want to connect to the sidewalk bump dot png, and a link to that file. Click Openimage. Now, I've got a bump map applied onto both of those materials, and I can check this. I can get in real close on that ground plane. Just set up my view, and again, disconnect the base color and again, set that base color to no saturation so we can verify that, in fact, there is a bump effect applied. Cool. I'll reconnect the color output of that sidewalk base dot png file to the base color input of the material. And now we've got color and bump maps applied to both of those surfaces. 14. Remapping colors: To wrap up this course on materials and mapping, I want to show you how to use a color ramp. This is one of the most useful nodes in the entire Shader library. It can do many, many different things. In this case, I'm going to take a grayscale image that I've prepared in advance and remap those grayscale colors onto entirely new RGB colors. This gives me the ability to change or art direct those colors directly within blender. I don't have to go back to an image editing program like Photoshop in order to change a particular color. It's all editable directly within the Shader Network. And it's through the magic of the color ramp node. Let's start by adding the image texture that I previously prepared. I've got the ball selected. Got the shader editor open. Here's the principal BSDF material that's assigned onto that ball. I want to connect something to the base color. Click and drag on the base color input. Release the mouse. We want to add an image texture, and if it's not in the list, you can start typing in IMAGE. Connect the image texture color output. Click on Image texture color, position that node, and then click to complete that operation. Of course, we need to browse for the image. Click on Open. Go to the current projects input Textures folder, and it's called ball remap Colors dot png. Click Open Image. And now if we orbit around, we can see that we've got a series of grayscale bands applied. Now, this is a special case here. I'm not going to use these colors directly. I'm going to use their raw pixel values, and I'm going to take those values and map them onto something else. So this is a special case where I'm not actually using a color as a color, but I'm using a color as a mechanism. And in that case, I want to set the color space of the image texture node to non color. The default is SRGB, which is going to gamma correct the image. But I want to choose non color from the list here. Again, this is a special case. And now we see there's less contrast. Okay, now we need a ramp gradient node. And one of the cool things about the blender Shader Editor is I can drop a node on top of a connection wire, and that'll cause those connections to be made automatically. I'll move these nodes away from one another, create some space. And I want to create that ramp node. One way to do that is from the search engine. Just use the hot key Shift A and then start typing in. In this case, it'll be amp RAMP and there it is. We want to connect to the color ramp. Lick on that. Now the nodes created, and as always, I'm moving the node around without pressing the mouse button down, position that node over that connection wire and then click and that connections made. The output of the file node is going into the color ramp. The output of the color ramp is going into the material. And right now, it's not doing anything. It's got a linear ramp here. So it's just turning black into black and white into white and anything in between to whatever the original grayscale value was. And if I move these color stops around, we can see that we're able to cause that to occur on different locations based upon the original texture file. And if we move the other stop around, we can see, Okay, we're determining where we want these black and white colors to be placed on the surface. In this case, I don't actually want any interpolation. I want to just have a bunch of solid colors. I'm going to select the first stop on the left at stop number zero, and I've got an interpolation type up here, which is set to linear. I'll set that to constant. And now as I move these stops around, we can see we're only getting solid black and solid white, nothing in between. Okay, I'll move this one all the way over to its position of one and this one all the way over to its position of zero. And if I orbit around, we'll see the entire surface is now black. And that's because this black value is being held until it reaches the very end here, and then it's transitioning to white instantaneously. If we set this to some value other than one, then we will see that, Okay, we are getting some amount of white there. Okay, so now we want to create a bunch more of these stops. The way we do that is just control click Control click, and that creates a new stop. It's automatically selected, and we can plug in its position numerically here. So let's do that. We'll set this one to a value of 0.1 and then Control click again, set that new one to a position of 0.2. Control click, and just repeat that process, incrementing that position value by 0.1 for each successive color stop. Okay, now I've got actually 11 stops inserted here. I've got a total of 11. The first one is number zero, and the last one is number ten. So that's a total of 11. We actually don't need this last one, so we can remove it. Select that stop and click the minus sign. Then we'll just go around and give color values to all of these. I can select that first one, Color Ramp zero, and click on its color down here. It's black currently, and I can set it to white. And if I orbit around, we'll see that we've got some white at the bottom here. It's a little easier to see if I select the object, and then I can orbit around that selected object. Okay, so I've done the first one, then I'll select the second one, and we'll just start plugging in some colors here. I can make this first one red. And then stop number two, we'll make it yellow. And so that's going to be red plus green. The third one. Let's set that one to blue. Bring the blue amount up. And just keep repeating that process and art directing all these colors. I'm just using these primary colors because it's easy. I'm not actually making a beautiful work of art here, but I'm just demonstrating how we can reassign these colors, but they can be any color you want. Okay, now I've assigned colors to all ten of those color stops, and this is looking pretty good. Again, I haven't done a beautiful job here. I haven't made this into a work of art, but I've now reassigned those grayscale values to RGB colors, and I can change those again at any point. If we get in really close with Control Middle Mouse, just position this so that we can see this really clearly. We will see some fringing here. So right where there's a transition, you might see a little line there, and that's happening because blender is doing internal filtering on this texture directly within the image texture node. So it's actually softening up the transition there, and we don't actually want that to happen. We can disable that at the very top here, we've got the interpolation or the blending of nearby pixels. You want to set that instead of linear to closest. And now we don't have any of that fringing artifact. Very cool. So now we've got this fully art directable remapped color scheme on this ball. And that concludes our course on materials and textures. 15. Next Steps: Alright, we've got materials applied onto our objects in blender, and we've learned the importance of setting up a neutral environment for material testing, including the all important color management settings. So now we've got objects with materials on them, but we need to also frame our scene with a camera and apply some basic lighting. And that's what part three of this course sequence is going to be all about camera and daylighting. I'll see you in part three.