Cell Fluids addon: Review & Tutorial

the other day I noticed a new water simulation addon called cell fluids it had reached the front page of blender Market which is not easy to achieve I took a better look and bought it instantly because it looked useful so under the hood cell fluids is actually a geometry nodes and simulation nodes setup and it creates these cool and convincing water simulations in real time and that is amazing if you have any experience with water simulation you know that they are far from real time it's important to understand that this is a trick it is not real water simulation and it is not based on particles the add-on developer calls it 2.5d simulation and that is why it runs so fast but it also means that the system has limitations they are clearly stated on the product page if you're considering buying this addon it's best to understand how it works the goal of this video is to show you how to use the addon it's actually quite easy and intuitive and hopefully this video helps you decide if the add-on is right for you or Not So when you buy the add-on you'll be able to download the files you mainly need this ZIP file so download it without unzipping it the PDF file is a written manual and the blend files are example scenes to install the addon in blender go to Ed preferences addons click install find the ZIP file that you downloaded and click install Aron activate and the Aron is in the end panel under cell fluids to create a new simulation you can click the new Floyd button and that creates a box where the Floyd simulation will happen this is the domain and you can change its um size on X and Y and also its height interestingly the X and Y values affect the performance the bigger the values the slower the performance but the depth value does not affect the performance so just set it to exactly what you need then you have a couple of collections right now even if you play the animation nothing will happen so we need to set the fluid collections first we have initial so I'm going to press this button and it will create the initial fluids collection for me so I'll click on this collection and now I can go to the 3D View and press shift a and add some objects they can be any shape you like I'll add a cube and you'll see that right away something is happening I can add also sphere and now if I play the animation the initial fluid objects created some initial fluids and it dropped into the simulation domain and it is now being being simulated if you enable material preview you'll see that we have a very nice water material already for these initial fluid objects you can actually go to the object properties viewport display and change the display type to wire okay now if we play from the start you can see the initial fluids and then they just drop into the domain and they are simulated and you can see that we have some foam which disappears over time we have Ripples and as I said earlier this is not real water simulation but it looks very convincing if you look at the first key frame you'll see that the water is already stretching from the initial object all the way to the floor so this is because of the trick that this system uses uh and there there is no way to avoid this so this is one limitation that you may want to watch out for so that is initial fluid if I select the the main again I'll get my options again and I can create the inflow collection so let's just grab the sphere Shifty and duplicate it and then press M and move it to the inflow collection and then try to simulate again and this should help you understand what inflow does unlike initial fluid it doesn't just generate a limited amount of initial fluid but it creates a constant inflow of water this object can be animated right now if I move it nothing will happen that is because uh the whole simulation has been cached I can select the domain and change anything here let's just set this to 11 and then back to 10 and that will will reset the simulation go to the beginning of the animation press play and move around this object and you'll see how it creates water exactly where it is and I can create key frames for this object and now the water is simulated as uh this object moves next we have outflow which will create a collection for objects that will allow uh water to be drained out of the simulation domain so let's create the collection select it and create a new object such as a monkey and let's try to simulate and you'll see this Vortex this is basically because the monkey is creating a hole at the bottom of the simulation domain and the water is draining through it so again this looks quite convincing for a fake effect uh so let me delete these initial fluid objects in this one I'll make smaller so that it generates less water and let's make the monkey bigger to see the effect better make it wireframe okay so now we can clearly see where the outflow is happening next we have ground and effectors and these are two different ways to create objects that will collide and interact with the water the difference is that ground is is for static objects and affectors is for animated objects that can interact with the water so let's try the ground first and simulate from the start and you'll see the water coll fighing with these objects and then eventually flowing over them let's create a larger domain so that um it is not filled up so quickly and now you can see the effect of these uh ground objects more clearly so if we are simulating a river with rocks and stuff then the whole river bed and any rocks in it will be a ground object and we'll see a demo scene a little bit later now let's create effectors and an fector object now I can start simulating and if I move this object you'll see how it creates Ripples and some foam in the water so that is what effectors do in a nutshell if I just let it stay here and simulate you'll see that unlike ground objects effectors to not stop the water as much they just influence the surface with additional waves and foam now this is a little bit hard to see and this might be a good opportunity to show the set render settings button if you click on it it will recommend changing a couple of settings for Ev and cycles and it's really nice that it doesn't just change them but it shows you what it's going to change and it even giv gives you the option to change it or not so I'm going to press okay and then simulate again and now you should be able to see the effect of this effector a little bit more clearly because we don't have the EV noising in the viewport anymore and actually I hadn't set up the effectors fully even though they kind of already work we have to press this setup effector modifiers but button and then simulate again yes and now you should see the effect of the effectors even more clearly uh it creates a lot more foam and waves and as with any sort of simulation keep in mind that results get cached uh so here for example I can see the ripples that I created in the previous um uh simulation so all I need to do is change change something for example rescale this uh sphere and try again and now the simulation will happen in real time and not from the cache then we have some additional settings um time scale can be cool for slow motion effects so here we we can see the water flowing into the domain much much slower if I set um time scale to 0.1 and I can also change it in the middle of the animation which is school so now it will start flowing a lot um faster and there are some additional post effect there is post displacement which will displace the water a little bit there's post noise which gives Some Noise to the water additional foam so that enables and disables these foam objects fill sides will fill the sides of the domain and then fill bottom will fill the bottom now here is a feature that I absolutely love the bake flow Maps So currently I have stopped the animation and simulation and I have this result here if I just press this button this will remove the whole simulation aspect of this addon but it leaves me with the exact water model that I had before clicking the button now if I play the animation you'll see that I have the illusion of the water flowing without changing its shape and that can be great for creating rivers and stuff like that I'll show you an example in a second now let's check out the demo files by that I mean the blend files that come with the uh cell fluids addon the first one is this waterfall and you can see how it filled out this River in real time and we have nice foam simulation around the waterfall so very nice and make sure to check out how the collections are set up so we have the ground collection which is the whole river bed we have this inflow object it's just a simple Cube which adds water over and over we have some initial fluid which is outside of the simulation So currently it does nothing you can just place it inside and then it will do something but I don't think it is meant to do it in uh this scene so let's undo and we have this outflow object which makes sure that the river doesn't overflow so when the water reaches this place the simulation will start losing water this scene is a good candidate for baking flow Maps so let's say that we reach this point I'll select the domain and click bake flow maps and now we have a seamlessly flowing river which we can use in a scene that doesn't need to be simulated it just needs to feature a river another similar scene again we have the ground objects here and actually outflow and um initial fluid are outside the simulation the another important part is this inflow object again just a cube that will keep adding fluid to the simulation again looks great and you can um make the flow map at the end to have a seamless looping effect and finally we have this uh Beach simulation which is a very common test in water simulation so here we have this initial fluid I don't think we have any inflow objects yeah they're outside um the ground is obviously all of these rocks and the beach itself the outflow object is also outside and then we have an affector which is this box here and what it does is it rotates and pushes the water and that creates the waves so if you try to simulate this with a standard fluid simulator using particles such as flip fluids or blender mflow it will easily take days and weeks to create tweak and render the animation but with cell fluids you can do it in real time so these demo scenes should show you what the intended use of the Aron is one thing that you should know note is the size or scale of these simulations all of them are around 10 to 20 to 30 m and we are simulating a relatively large body of water if you want to simulate something larger that shouldn't be a problem you just have to increase the X and Y uh size so that the domain can Encompass your simulation the simulation might get slower but it should be possible but what is hard to achieve is very fine simulation so for example I was testing filling a small room using cell fluids and I found it difficult to create small inflow objects a possible solution for that is to scale up your small scene so that it is not in real scale but say 10 times larger that was my in-depth overview of the sell fluids addon I think it was a good overview of how the addon works and what some of the limitations may be so have fun with your water simulations

Channel: CGDive (Blender Rigging Tuts)

Views: 16,029

Keywords: blender3d, b3d, rigging

Id: Sp_mR5eCAQY

Length: 16min 1sec (961 seconds)

Published: Tue Oct 17 2023