Fluid simulation in blender 4. 0. 2

1. Introduction: Adding fluid in your blender can seem scary if you're just starting to use fluid simulation, but don't worry. Fluid simulation becomes really easy once you figure out how does it work. In this class, I will teach you how does the fluid simulation work. How to add it in your sin in blender. How to make it look better with the particles. How to add different density values to your fluid. And a lot more other interesting tools that will help you to make a beautiful fluid simulation. So let me show you how to make a fluid simulation. Now, just before we start, please forgive me if my pronunciation of a certain words is a little weird. English is second language to me. And with that out of the way, let's jump into the fluid simulation. 2. Seting up fluid simulation: Now this is how we are going to explain the liquid simulation. We are going to make one simple liquid simulation and then we will do a breakdown of that simulation to explain how does it work. Open your blender and delete everything in your sin. Now to make a liquid simulation, we will add a UV sphere. Now press three and type quick liquid and select it. Okay? Now you can move this time line a tiny bit up and now we have this simple liquid simulation. Let's explain how does it work. You see, whenever you want to add a liquid simulation in your sin, your simulation will need two objects. One object that is going to be the flow and one object that is going to be the domain. Now if we select this UV sphere and if we go under the physics, you can see that here this sphere has enabled fluid under the type it is set to flow. When we used quickly quit to add this simulation into our scene, blender automatically set this sphere as the flow object. And we also got this cube. As you can see, this cube is set as the domain under the physics. Now let's explain what each of these two objects actually does. Let's explain the domain first. Now your domain represents the area in which your liquid can function. If we play this simulation, you can see that this liquid is flowing free until it touches the domain and it can't move any further than that. Always make sure that everything you want your liquid to interact with is within the domain. Since your liquid will only be able to work within the domain with the domain explained. Let's move on to the flow object. The flow objects are the source of the liquid. All the liquid in your simulation is going to come from the flow object. Now this has been a very over simplified explanation of these two objects. Let's explain them in a tiny bit more detail. We will explain the flow object first. 3. Flow object: Now guys, like I mentioned in the previous lesson, the flow object is going to be the source of the liquid in your simulation. All the liquid that is in your simulation will come from your flow object. However, guys, flow objects have a few interesting settings which can be used to get different results for your simulation. We select our flow object, and if we go under the physics, you can see that we have this flow behavior option here. By default it is set to geometry. Now if we open this setting, you can see that we also have this Inflow and Outflow option as well. Now let me explain what each one of these options does. Now, like I said, geometry is the default setting and what it will do is it will cause your flow object to be filled with the liquid. And when you play your animation, all that liquid is just going to drop straight down out of your object. Now this option is good if you always want to have the same amount of liquid in your simulation. But what if you want your object to keep adding liquid into your simulation? Well, for that we have this Inflow option. If we switch this flow behavior from geometry to inflow, and if we play this simulation, now you can see this object is now constantly adding new liquid into our simulation. Now this is really useful if you want to increase the amount of liquid in your simulation. But what if you want your flow object to at a certain point stop adding liquid into your simulation? Well, for that we have this use flow option. Use flow controls, whether or not is your object going to add new liquid into your simulation. As long as it is enabled, this sphere will continue to add liquid into our simulation. Now this is how you can stop your object from adding new liquid. Let's play this animation. Pose it at the frame eight. Now press this dot next to the Use Flow setting to add a keyframe to it. Now move one frame forward and disable this use Flow. Now press this dot to add a new key frame. Now if we play this simulation again, we can see that now this object stops adding liquid into our simulation when we reach the frame 18. Okay, with this explained, we covered everything we needed to cover with the inflow setting. Now let's move on to the last flow behavior, the outflow. However, to explain how does the outflow work, we will need to add a new object into our simulation. Let's add a cube and place it right below the UV sphere. Now to set up this cube as the flow object, we need to open the physics enable the fluid and switch the type to the flow. Now switch the flow type from smoke to liquid and switch the flow behavior from geometry to outflow. Now that we have set up this cube as the Outflow object, let's play this simulation and see what will happen. As you can see, the liquid is disappearing the moment it touches this cube. Basically, what Outflow setting will do is it will cause your object to behave like a sponge. The moment your liquid touches the object that is set up as the outflow, your liquid will be absorbed by that object. When it gets absorbed, it will disappear from your simulation. This is very simple way you can use to decrease the amount of liquid in your simulation. Now, we added this cube just to explain how does the outflow setting work. Now that that's explained, let's delete this cube. Let's play this simulation also, guys, in case your liquid doesn't follow all the changes you made in your simulation. What you need to do in order to fix that is you need to reset your simulation. Now to do that, select your domain and under the physics properties, simply change any settings and then change that setting back to how it was previously. Now if we play this simulation again, you can see that this liquid is once again moving correctly. With this, we have explained the flow object. The next thing we need to explain is the domain. 4. Domain and the effector: Now in the previous lesson, we explained the flow object. In this lesson, we will explain the domain. Now with the domain, we have a lot to talk about. So let's just jump into it. The first important setting we need to explain is the resolution. What resolution controls is what is going to be the quality of your liquid. The higher you set up your resolution, the higher is going to be the quality of your liquid. Now, by default, the resolution is set to 32, and that is a really low resolution. However, I recommend you to keep your resolution at this low value for now, and I'll explain why later. The next setting we need to talk about is the timescale. This does exactly what it sounds like. It controls how fast is your liquid going to move. The higher value is going to make your liquid move faster, as you can see here right now. The lower value is going to make your liquid move slower, as you can also see with this simulation here. Okay, now let's scroll down a bit until we reach the mesh settings. And now listen to me carefully. Up until this point, our liquid has just been a bunch of blue and green dots. But we need to give our liquid an actual mesh. To do that, just enable this mesh setting here, and now we have a mesh for our simulation. Let's quickly play this simulation with the mesh. This looks really, really good. Now we can move on to the chase settings here. Now guys, listen to me carefully because this part is really important. One thing you need to understand about liquid simulation is that your simulation is going to be saved as its own separate file. Sure, the blender scene in which you'll use your simulation will be saved like any other blender file, but your liquid simulation will have its own save file separated from the rest of your blender. What this chase area will allow us to control is how will our liquid simulation be saved? Now first we need to talk about this button here. This button will allow us to control where in our PC will our simulation be saved. Simply press this button and then pick a place where you want your simulation to be saved, and then just press T. Now next we have the frame start and frame end values. Here they are super simple. They control when will our simulation start and when will it end. Frame start controls, when this simulation will start and end controls, when is this simulation going to be finished? Whenever you're using liquid simulation, make sure that these values are set up correctly so that your simulation starts at the right time and that it also ends at the right time as well. Now it's time that we move on this type setting here. Now guys, listen, whenever you have liquid simulation, you will need to bake that simulation. What this type setting here controls is how your simulation will be baked. By default, this is set to replay. What that means is that this simulation is being baked in real time while you're playing this animation. If we play this animation, you can see how this simulation is moving. Because as long as this type is set at replay, your simulation will be baked in real time while this animation is playing. Now this replay type is really useful while you're setting up your simulation, but it's not all that useful. Once you have set up your simulation for the final render. For the final render, we will use one of the other settings here, but we won't change this type setting just yet. There is still one thing we need to set up on this simulation. Now that last thing I still need to show you is how to make your liquid interact with the other objects. Now you may think that's pretty simple. You just add an object to your sin, and boom, your liquid will instantly interact with it. But it's not that simple. Let's add a cube in our sin, let's place it right below the liquid. Now if we play this simulation, you can see that this liquid is not interacting with this cube, it's just moving straight through it. In order to make this liquid interact with this cube, we need to set this cube up as the effector. To do that, select your cube. Go under the physics here, enable the fluid and switch the type to the effector. Now if we play this simulation, you can see that this liquid is nicely interacting with this cube. Whenever you want your liquid to interact with some other object, just make sure to set up that object as the effect or under the physics guys in case your liquid doesn't interact with your object. Even though you set up your object as the effector. This is what you can do in order to fix that problem. As you can see, this liquid is not interacting with this plane, even though it is set up as the effector. Now this is what I'm going to do to fix that problem. I am going to move these settings here. As you can see, the effector objects have this surface thickness. What this surface thickness controls is how close does your liquid needs to be to your object in order for your liquid to interact with your object. Now let's set this surface thickness to a value of 0.5 Now if we play this animation, now you can see that now this liquid is nicely interacting with this plane. This is one simple trick you can use if you have problems with the effector. But you only need to be careful not to set this surface thickness value too high. Because if you do that, your liquid is going to interact with your object before it actually physically touches it. If I drastically increase the value of this surface thickness, and if I play this simulation now, you can see that this liquid is behaving like it already touched the plane. But in actuality, it's just floating in the air. Be careful not to set this surface thickness too high and you won't have any problems with this cube Set up, we are ready to prepare this liquid for the final render. Now guys, what you need to do is the following. Select your liquid and scroll down under the chase here. Switch this type from replay to modular. This modular type is what you need when you're planning to bake your simulation for the final render. Also guys, make sure that you enable this is resumable option down here. Now guys, let's scroll up all the way to the top of the settings. Now it's time that we increased the resolution value. Now guys, earlier in this lesson, I told you not to touch your resolution until you finish setting up your simulation. There are two reasons for that. The first reason is that the higher your resolution is, the longer it will take for your simulation to be baked. Now, up until this point, our simulation was moving pretty fast. But remember, all this time the resolution was set at a really low value. I am going to increase the resolution to a value of 215. This value will give us the highest quality for the liquid, but it is also going to take some time for this liquid to be baked with this high resolution. Just remember that the higher the resolution is for your simulation, the longer it is going to take for your simulation to be baked. The second thing you need to keep in mind about the resolution is that the higher your resolution is, the bigger is going to be the file size for your liquid if your PC is short on the free space. Then you will run into some problems if your PC runs out of the storage while you're baking your simulation. Several times I was baking my liquid and my PC ran out of storage because I wasn't careful and that caused my liquid to stop moving midway through the animation. If you do run into the problems like that, I recommend you to set your resolution to a value of 175 or lower if needed. Setting your resolution to a lower value will decrease the file size for your liquid and it will also speed up the baking process. Also, I am going to decrease the length of this simulation. To do that, I will scroll down all the way to the chase and I will set up the end value to 125 or simulation doesn't need to be 250 frames long. And making this simulation shorter will decrease the amount of time this simulation will need to bake. If you want to, you can make your simulation even shorter. Now let's crawl back up again. And let's press this bake data button. Now our simulation is baking and now we only need to wait for this process to finish guys. While we wait, I'm going to show you one more thing now. You don't need to follow me along as I show you this. This is just something you can do while your simulation is being baked. Now to show you what this is, I waited for this simulation to be baked up to the frame 23. Now I'm going to pause the baking of this liquid. To do that, I am going to press the escape button. Now that the baking has been paused, I'm going to show you my progress. To do that, I'll open this wires port and I'm also going to move one frame back. Now you can see all the progress on my liquid up until this point. But I did not pass my baking to show you my progress. I pass it to show you this. Let's crawl down all the way to the chase. Now if you're wondering why I told you to enable this is resumable option here. Well, to explain that we need to scroll back up again. Now here where previously was baked Data button, now there are the resume and free buttons instead. Now what do they do If you press the free button? All the progress you made while baking will be deleted and you will need to bake this liquid all over again. This is what you press if you incorrectly set up your liquid. But if you press this resume button, then Blender will continue to bake this liquid as if you never passed it in the first place. This resume button is really useful if your simulation is taking a long time to bake and if you want to just quickly pass the baking just so you could see is your liquid being baked correctly. But guys, you will only have this resume option if you enabled is resumable setting here under the chase, make sure that you always enable this is resumable option so you could continue to bake your simulation whenever you posit it. Now I will press this resume button. Now let's wait for this to finish baking. Okay. Now that the data of our liquid has finished baking, the last thing we need to do is we need to give this liquid. To do that, let's crawl under the mesh, open the mesh settings, and just press this bake mesh button. Now we only need to wait for this mesh to finish baking. All right, now that our mesh has finished baking, we have this really decent liquid simulation. 5. Fluid texture and viewport render: All right guys. In the previous lesson we finished making this liquid simulation guys. If you managed to get a liquid simulation that looks like this, then congratulation guys. You mastered the basics of liquid simulation. All the knowledge you gained in the previous lesson is going to serve as the foundation for your skills with this field in blender. And it will allow you to make more complicated simulations in the future. However, guys, no matter how good does this liquid simulation looks, there is still one last thing I would like to teach you about liquid simulation. That one thing is the texture. If we open this view port here, you can see that by default Blender has given us this texture for liquid simulation. Now to best explain how does this texture look, we will need a cycles render engine. Go here under the render enable ambient inclusion and Bloom, switch this from B to cycles, switch this P from CPU to GPU. Set this noise threshold 2.5 enable the noise and set this start sample at the same value as your max sample here under the viewport. Okay now open this viewport here where we can see the textures in cycles. Now open the world. Press this next to the color, select the sky texture, three to ten, dust to zero, and er 2.25 Okay, now we have this nice set up that allows us to decently see how does this texture look. Now to best explain how does this texture look, let's go here under this shading viewport, let's open this final render view port here as well. Okay, now let's wait for all these samples under this view part to finish rendering. All right guys, this is how our liquid simulation looks. If we move here, you can see this is the set up blender made for the texture for our liquid simulation. By default, this texture already looks really good. Now this texture is really good if you want to make something like a water, but if you want to make something else, something that's not water, there are few settings that you can use to get a different results for your texture. First, we have this color. Color is pretty simple, controls what is going to be the color of your liquid. Okay, let's return this back setting. Next we have this roughness. What roughness is going to control is how much you can see through your liquid simulation. Right now, the roughness is set to zero which makes this liquid work like a glass. And by that I mean that we can see everything through this liquid simulation. But if we set this roughness to one, let's wait for all the samples to finish rendering. Okay, now you can see this liquid is now white, the same color as set up here. More importantly, now we can't see anything through this liquid. Keep this thing in mind. The roughness is going to control how much you can see through your liquid roughness of one will cause that you can't see anything through your liquid roughness of zero will cause that you can see everything through your liquid. If the liquid you want to make is somewhere in between, then just play with this value until you get the roughness setting you like. Okay, now we have this O setting here. Now I usually like to just leave this setting the way it is. This setting is going to mostly control how does the light goes through your liquid and every liquid is going to have a different IRL value. If you want to make water, then I recommend you to just leave this setting the way it is here. But if you want to make something like a honey or a milk, and if you want to give those liquids a nice IRL value, then what I recommend you is to just Google what the IRL values are for milk and honey. Yeah, really? I'm not joking. Just Google. Just type what is IRL value for milk and honey. Google is going to tell you that this is really simple solution to get answer to what value you need to set up here. Okay? Now we have this volume here. This here, This is going to be really simple. Let's just keep this quick. Let's just get over this quickly. First, we have this color. Of course, as you can see, this color controls what is going to be the color of your volume. However, as you can see, the volume is looking a little weak. Now what this volume controls is what is going to be the color of the center of your liquid? And by that I mean where you have the most liquid, this green color is going to be the most visible. But where the liquid is only surface level, then you are going to have a less amount of this green color. Now to better explain what I mean, let's go to this view port. As you can see, if we look at this liquid from down here, you can see that this liquid, it's not fully covering this domain right now. It's only covering the edges of it. What I want you to do now, moved here to a frame 50. Okay, now as you can see, this green color is immediately a lot stronger. If we open this view port here, now you can see that this liquid is no longer just covering the edges of the domain, now it's actually completely filling up this bottom part of the domain. Basically what you need to understand about the volume is it is going to change color where you have the most liquid in your simulation, but where your simulation is relatively rare, where you don't have much of your liquid simulation, then that liquid is going to maintain its white color. I hope that this made sense With this, we more or less covered all the basics of your liquid simulation also. Guys, one more thing. I think that this goes without saying, but in case you don't want your flow object, in case you don't want your sphere to be visible in the final render. Then what you need to do is you need to press this camera here under Seal Scene Collection. What this is going to do is it will cause your UV sphere, your flow object to be invisible in the final render. Okay guys, with this, we have explained all the basics of liquid simulation. Now let's go to this viewpot here. Now guys, there is still one more thing I would like to show you in this lesson. If we play this simulation, you can see that this viewport is now really slow. This is another downside of giving high resolution to your liquid. It is going to cause your viewport to be really slow. Now, if you would like to see how does your liquid look without this low frame rate before you actually render your animation. One thing you can do to achieve that is you can render the viewport of your animation. Now, when I say render the viewport, I don't mean that we are going to make the final render of your animation. No, I mean that when we render the viewport, we are going to get the video that will show us how our liquid simulation looks exactly as it is shown here in the viewport. To render your viewport, this is what you need to do. First, we need to add a camera and position it so that it is looking directly at our simulation. Next, we need to set up the output for your render. Let's go under the Render, and let's scroll under the file format, and let's switch it to video. Now let's pick a place where you want your blender to place your Viewport render. After you do that, simply select the view and then select Viewport Render animation. However guys, before we actually do that, we will make this animation a tiny bit shorter. Our simulation lasts only until the frame 125. Let's set up the end of this animation at that frame as well. Now you can select the view and press surrender Viewport animation. Now just wait for this to finish rendering. All right guys, my Viewport has just finished rendering and this is how my liquid looks. This is one really quick way you can use to check out how does your liquid look before you start making the final render. 6. Fluid particels: In the previous lessons, we covered all the basics of liquid simulation. In those lessons, we gained the knowledge that is going to serve as the foundation for your fluid simulation. However, guys, now it's time that we move away from the basics and start talking about more advanced factors of liquid simulation. One of those factors are the particles. Particles are the great tool that will add more life into your simulation and make it look a lot. This is how this simulation looks without particles, and this is how it looks with the particles. As you can see, particles are making this simulation look a lot better. Now, as great as the particles are, people often rarely talk about them online. In my research about the particles, I only managed to find two tutorials that talk about them, one on the Youtube and the other on the skillshare. The question is, if the particles are so useful, why people don't talk about them more often? Well, the answer is simple. It's because particles are hard. Correctly, setting up the particles can be a little difficult and time consuming, which is why the many people try to ignore them. However, guys, if you put a tiny bit more effort into your work, if you're willing to push that little bit further to set up the particles, you're going to get the fluid simulation that is going to be beautiful and worth the extra effort. So let me show you how to add the particles to your fluid simulation, how to use them to make your fluid simulation look absolutely beautiful. Now guys, to best show you how do the particles work, we will make a new liquid simulation. Simply open a new scene in blender. And let's delete everything in our scene now guys, in order for our particles to be the most visible, this new simulation needs to be splashing. The easiest way to make our simulation splashing is by adding a few objects that the liquid is going to heat. So let's say a few objects in our scene and let's place them all close to one another. Okay, now that we have these few objects in our scene, we are going to set them up as the effectors so that the liquid will interact with them. Now that these objects are set up, we can make our simulation. Let's add a cube into our scene. Place it back here, and this cube will be our flow object. Now guys, in order for this example to be effective, we need to make sure that all the liquid in our simulation is going to splash into these three objects. Now for that, we need a lot of liquid in our simulation to make sure we will get enough liquid. Let's use this scale tool to make this cube taller and wider. Now we need to make sure that this cube is on the similar height as these other objects. To do that, let's pull this cube up here until it's in the line with the rest of these objects. Okay, we placed this cube, but there is still one more thing we need to do before we start setting up our liquid simulation. You see guys, we changed the scale of this cube. And guys, I recommend you that whenever you change the scale of your object, that you reset the scale of that same object. One way you can use to know whether or not is your scale reset is by opening these object properties here. And if not, all scale values are set to one. Then you need to reset the scale. To reset the scale, simply press control A, then select the scale. Now as you can see, all of the scale values are set to one, which means that this cube has a reset scale value. Liquid simulation will look a lot better if your object has a reset scale. Just keep this simple step in mind. With this, we are ready to add a liquid simulation. Simply select the cube, press three and type quick liquid. Now we need to place all the objects in our scene within this domain. Let's scale this domain up so that all of our objects can fit in it. Now, just like we reset the scale for our cube, let's also reset the scale for this domain as well. Let's press control and select the scale. All right, now that we took care of our domain, we need to play with this effector objects a little. They are way too small. Let's scale them up. After you did that, you will need to reset the scale for every one of these objects. After you did that, you need to once again, nicely position them in your domain. Let's make sure that all of these objects are within the domain. Let's also make sure that they're close to the bottom of the domain as well. Actually, come to think of it, I'm also going to add a one more object into this simulation. I will add this cone scale, it up, reset the scale and nicely place it in the domain. Let's not forget that we need to set up this cone as the effector. Now that we set up this liquid simulation before we bake it, let's play it to see how does it look at the first glance. It looks good. But guys, just for better visibility, let's enable the mesh under the domain. All right, this simulation works. It's nicely interacting with these objects and it has the splash we're trying to achieve. Now it's time to start baking this liquid. After we do that, we will be able to set up the particles for this simulation. First, under the chase, let's pick the place where we will save this liquid. You can also move this timeline a tiny bit up. Now switch this type from replay to modular and enable is resumable. Now we need to set up our resolution. However, guys, in the previous example, we set up this resolution at a value of 250, but in this example, we will set it up at the value of 175. The reason for that is the following. Remember guys, when in the previous example I told you that the higher your resolution is, the bigger is going to be the file size for your liquid. Well, that rule applies double when the particles are involved, the particles are going to make your file size liquid simulation insanely huge. If you're not careful, your PC will run out of storage and if that happens, your simulation will not work correctly. When you're working with the particles, it is crucial to cut corners on the file size wherever you can. Decreasing your resolution will not only reduce the file size for your liquid, but for your particles as well. Keep in mind that if your PC runs out of storage while you're working with particles, one thing you can do to improve the situation is to decrease the resolution. The resolution of 175 will decrease our file size and still give us a good looking simulation. Now let's press this bake data. Let's wait for this to finish baking. Okay, my data has just finished baking. Let's quickly play this simulation to see how does it look. It looks good. My simulation would have had a good splash even without these four objects. But now that they're here, let's just leave them there. Now let's bake the mesh as well. Okay guys, now that the mesh is baked, now it's time to finally start playing with the particles. The particles are just above the mesh. So let's open these particles settings here. Now guys with the liquid simulation, you have three types of particles, spray, foam, and bubbles. Each one of these particle types have their own features that makes them useful, each in their own unique way. Spray will cause your particles to form everywhere your liquid goes and splashes to foam will cause your particles to form on the surface of your liquid and the bubbles will cause your particles to be formed within the liquid. Each one of these three particle types is useful in their own way. For each simulation that you will make, you will need to decide which one of these particles is going to be the most useful. One more thing to keep in mind is that the faster your liquid moves, the more dynamic it is, more particles you are going to get in your simulation. Let's enable these spray and foam options here. Now let's crawl down to the bottom of these particles settings. Now guys with the particles, one thing that is crucial that you understand is that you must never have too many particles. If you add too many particles in your simulation, you are running with the risk of crushing your blender. Now to make sure that we never have too many particles in our simulation, we will play with these four settings. These two settings control how many particles will be added into our simulation. And these two control what is going to be the lifetime of those particles. Now to get the decent looking particles and not to get too many of them in our simulation, we will set the value to 40, this one to ten, this one to ten as well. And this 123, this set up usually gives me a good looking and functioning particles. In case this set up is adding too many particles for your blender to handle, I recommend you to decrease these values. These values will put less pressure on your blender and still make a good looking particles system. Now guys, after you have set up these particles, I highly recommend you to save your progress because now your blender is at the highest risk of crashing. Let's quickly save our file. Now that we did that, let's press the baked particles button and let's wait for these particles to finish baking. All right guys, now that our particles have finished baking, we have to give these particles a mesh. To do that, let's add a simple icosphere. And this icosphere will become the mesh for our particles. Now this pycosphere is in the liquid, but before we move it out of there, we need to do this. You see guys, Whenever you add a new object into your skin, you will get an icon similar to this one here. If you press it, you will get a few extra options for your object. Now the one we are looking for here is this subdivision setting. Let's decrease this setting to one. Doing so will decrease the amount of faces we have on our Icosphere. Trust me, our Icosphere needs to have as little faces as possible. Now that we did that, we can move this Icosphere out of this simulation. All right, now it's time we turn this icosphere into a mesh for our particles. To do that, let's select our liquid and let's open the particles properties. Now select these spray particles here, and open the render. And switch the render from halo to object. Next, increase this scale random to one and set this scale value to 0.02 Next, select this icon and press your Icosphere. Now as you can see, all of our spray particles have taken this icosphere for their mesh. Now guys, one thing you can immediately notice is that these particles are drastically slowing down our viewport to fix that problem. Let's select this screen next to the spray here that will hide the spray particles in the viewport. Now let's set up the foam particles the same way we set up our spray particles. First, press the screen to hide them. Switch this to object. Set up both of the scale values and select this icosphere as the mesh. Now immediately save your file. Now the last thing we still need to set up is the texture for the particles. However, guys, before we do that, we need to make sure that we can use these particles. Now, you may be wondering, but we bake them. Why would we not be able to use them? Well, simply put, because these particles still may crush your blender. Now, I told you that if you have too many particles in your skin, that your blender may crash. But just because we have baked these particles doesn't mean that we are out of the danger of crushing the blender. If one of the frames in this simulation has too many particles, then the blender is going to crash when we come to that frame. That can be especially bad if it happens while you're rendering your animation. Now to make sure that the blender will be able to handle these particles, we will do one simple test. We will render the view part of this simulation. If the blender can handle rendering the viewport, it will also be able to render the final render. But since rendering the viewport is a lot lot faster than the final render rendering, the Viewport will be a simple way of making sure that our blender will be able to handle rendering these particles. Now we will render the particles just like we did in the previous lesson. We will add a camera into our scene, position it so that it is looking directly at the simulation. Let's also move this icosphere out of the camera's view guys. In order for this test to work, we need to see the particles in the viewport. Let's select this liquid, go under the particles and simply press these two screens to make particles visible in the viewport. Remember guys, we are rendering the viewport. In order for this test to work, particles need to be visible in the viewport so that there be visible in the viewport render as well. Now go under the output, set up a correct file format, pick a nice place for your viewport render. Now guys, if you did not save your file, do it now, because if your Blender crashes, you need to make sure you won't lose any progress you have made. Now simply go under the view and select Render Viewport Animation. Now let's wait for this to finish rendering. If your blender can render this Viewport all the way to the end, you can move on to the next part of this lesson. But if your blender crashes or if your recording doesn't look how it should, then you will need to rebake your particles with a set up that will add less particles in your simulation. And then you need to render the viewport again. All right guys, My blender managed to render this viewport for this animation and that is great. That means that my Blender will also be able to render the final render as well. If your Blender managed to render your Viewport as well, you can simply continue to watch this tutorial, but if your Blender crashed or if your Viewport render Look good, then you should decrease the amount of particles in your animation and bake your particles all over again. Also, if your PC is running out of free storage, I also recommend you to decrease the resolution of your liquid a tiny bit. Now guys that we know that our blender will be able to render this simulation, it's time for us to give a texture to these particles. To do that, let's open this viewport so we could see the textures. As you can see, the blender has already given us this pretty decent texture for the liquid, but we still need to texture our particles. To do that, simply select this icosphere, that is the mesh for our particles, and go into the shading. Now press this new button to make a new texture, and this is what we will do next. Decrease this roughness of this node all the way to zero. And then add mas grave texture. Plug its height into the base color. Now on the mask grave texture, increase the details to the maximum, all the way to the 15. Then increase the value of this dimension to a value similar to this one. Now decrease the scale to a value similar to this one. Next you need to add the color ramp and place it between these two nodes. Now move this white color close to the other side of this color ramp. Now that we have set up this color ramp like this, you can improve it by changing this white color to a really, really light blue color. Now simply duplicate this color ramp and switch this blue color of this new color ramp back to pure white. Then plug the height of the mass grave texture into the color ramp. And then plug the color of the color ramp into the alpha of this node here. With that, we finished making this texture for particles. This is a really good looking texture that will work really nicely for our animation. Now guys, one more thing. If you don't want your flow object to be visible in the final render, you need to disable this camera next to your flow object here. That will make your flow object invisible in the final render. Now guys, if you want to, you can also give the four objects some texture as well. I won't add any fancy looking texture to them. I will just set this roughness to zero and give them all different colors. These objects aren't really the focus of this animation or this class. There is no point in giving them a really fancy texture with all four of the object texture, we are ready to render this animation. 7. More useful tools: And with the particles explained, we covered all that you need to know in order to make a beautiful fluid simulation. If you guys can make a fluid simulation with the particles, then tap yourselves on the back. Because if you did that, you figured out all that you need to know with fluid simulation. But there are still a few interesting things that you can do with a fluid simulation. While you don't need to know these things in order to make a fluid simulation, they are still good to know since they can help you avoid some problems and get a better result with the fluid simulation. In the rest of this class, we will be talking about those useful tools. Let's get started. 8. Viscosity: Now the next thing I would like to show you is how to add different density values to your liquid. For that, I added this monkey head, that is going to be our effector. I added this UV sphere that is moving left and right. This UV sphere is going to be our flow object. Now let's quickly set up a very simple liquid simulation for these objects. Make sure that the domain is big enough to fit all of your objects and the liquid, don't forget that you need to set up your monkey head as the effect. Also, one more thing we need to do is we need to set this UV sphere as the inflow under the flow settings. Now let's immediately enable the mesh for this liquid under the domain. Now let's play this simulation. As you can see right now, this liquid is behaving like all other liquids we made in this class. This liquid is behaving like a water. But what if you want your liquid to be something that's not water? If you want your liquid to be slime, go. Or honey, something that is a lot more thicker, a lot more denser than water. Well, for that we have this viscosity value here. Let's enable it. We can also open the viscosity settings immediately. Now guys, under viscosity, we have this strength value. And what this strength value controls is how dense is going to be your liquid simulation. The higher you set up your viscosity strength, the higher is going to be the density of your liquid simulation. Now if we play this liquid simulation with viscosity enabled, you can immediately see that this liquid is a lot more denser than it was before. Guys, don't forget, the higher you set up your viscosity strength, the more denser is going to be your liquid. Now here are a few examples of this liquid simulation with different viscosity values. All these simulations have exactly the same settings. The only thing that changed for them is their viscosity strength. As you can see, the higher we set up the viscosity strength, the more denser the liquids become. This is one simple trick to keep in mind while you're working with liquid simulation. 9. Substeps: Another thing that can be really useful to know are the substeps. What are the substeps? Well, for that we will need a new liquid simulation. For this new liquid simulation, I added this UV sphere. Now let's just press Trim and let's add a simple liquid simulation. Now in order for this example to be effective, our domain needs to be a really big, let's really quickly scale up this domain like this. Now reset the scale now for a slightly better visibility. Let's increase immediately this resolution. Let's increase it to 64. We can also immediately enable the mesh for this liquid. Now what we need to do next is this. Let's move this timeline a tiny bit up. Select our U sphere. Now press this dot here. And by doing this, we set up the blender so that anytime we made changes in this scene, blender will automatically add a key frame for that change. Now guys, what we need to do the following, is this. Up until this point, our flow objects in our simulation have either been completely still or they were moving really, really slowly. However guys, if your flow object is moving and if your flow object is moving really fast, then you might have a tiny problem. To demonstrate what that problem is, we are going to quickly play this simulation. Then press G. Now, quickly, just move your mouse around so that your UV sphere will move within this domain. Now as you can see, we have a new key frame for each one of these movements we made with our UV sphere. Now make sure that your flow object is the inflow. I'm going to quickly set this UV sphere as the inflow object. Okay, now let's go back to the first frame and let's play this simulation from the start. As you can see, our liquid simulation has a problem. You see this UVsphere is not adding a consistent amount of liquid throughout this entire simulation. Sometimes it's nicely adding liquid into our simulation. But when this UVsphere is fastly moving, then this UVsphere is just adding the drops of liquid for every frame of our simulation. Now guys, this is one problem that you are going to have with a fast moving flow object. Whenever your flow object is moving fast, your blender is going to struggle a tiny bit how to calculate your liquid now in order to avoid this problem, In order to avoid having these drops of liquid and instead to make cover flow object consistently add the same amount of liquid. Throughout this entire simulation, what we are going to do, we are going to increase the sub steps. Now what these substeps are going to control is they are going to make or blender, calculate how would this liquid move between each one of these frames. Now let's simply increase the substeps 0-3 Now if we play this simulation again, now you can see we no longer have the drops of liquid. Now this flow object is consistently adding the same amount of liquid throughout this entire simulation. Guys, just keep this in mind. If your flow object is moving fast, then your blender might struggle to calculate how should your flow object add liquid into your simulation. If you have that problem, just increase the substeps from zero to a higher value. And that will cause your liquid to calculate how should this liquid move between each one of these frames. And that will cause your liquid simulation to look a lot, lot better. 10. Initial velocity: Now guys, this is one last thing I would like to show you in this class. Now, for this example, I made this very simple liquid simulation. Now guys, if we play this liquid simulation, you can see that this liquid is behaving like it does in any other simulation we made all the liquid is just dropping straight down out of your flow object. However, guys, what if you don't want your um, flow object to just drop all of your liquid straight down. What if you want your flow object to throw your liquid out in a specific direction? Well, in that case, you need to select your flow object. If you go under the physics, you will see that your flow object has this initial velocity setting. What this initial velocity setting will help you is it will allow you to throw your liquid in a specific direction. If we enable this initial velocity settings, you can see that they, the x, y, and z values. Now, each one of these three values represents one of the three axis we have in blender x, y, and z axis. By changing the values, we are telling blender in which direction we want this flow object to add this liquid. If we change this y value here, 0-10 you can see that what this flow object is doing now is it is adding a liquid the direction of this y axis. If you want this flow object to add this liquid in the opposite direction, simply switch this ten value from ten to minus ten. And as you can see, now this flow object is adding this liquid in the opposite direction. If you want this effect to be weaker, what you can do is you can switch this value of minus ten to minus five, as you can see. Now this flow object is still adding the in this direction, but now it is putting a much less strength into throwing the liquid into the direction of this y axis. Guys, you can totally add a multipolar values into these settings here. Now what do I mean by that? If we look at this simulation from above, if we switch this x value here, 0-5 okay? Now you can see this liquid is being thrown directly between the x and y axis. These settings here are really a nice way you can set up your flow object to add liquid into any direction that you like. If you want your flow object to add a liquid in a specific directions, just play with these three values here and your flow object will add liquid in the direction that you like. Okay guys, this has been a last interesting tool that I wanted to show you in this class. 11. Outro: With this, you have completed this class. Congratulations guys. I hope that this class helped you learn a lot of cool new things that you can do in blender. And that you are going to put the knowledge I gave you to good use. And guys, don't be shy. Feel free to show all of your beautiful work, all of your beautiful fluid simulations you learned how to make in this class, in the class projects here at Skillshare. So that all may see and enjoy your beautiful work. Guys, if you like this class, please leave a good review, and I hope to see you again soon in the next class. A