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3D Fluid SimulationsHave you ever received an email from a client that sent shivers down your spine? It might include this paragraph: Hey, I need you to create a fluid animation effect for me; heres a reference photo of a beautiful (insert photo of waves, ocean, splashes, beer pour, etc.). You have till Tuesday.True story, I have a friend who received the exact email above, asking him to create an animation of a wave splashing back and forth in a container. He spent 30 hours trying to simulate it, and in the end, his client hated it, and my friend didnt get paid a penny.In this blog post, I want to help you avoid this situation. While the email will still give you the shivers, at least you will have a better understanding of the best practices for making fluid simulations in 3D.This guide isnt going to give you the specifics but instead will provide you with a general overview of the available tools and the best ways to get the results you want. Lets dive in; the water (fluid) is warm!Why Fluids?If youre a motion designer or VFX artist, then you cant go long without a request to make fluids. It has become a key part of our job as artists, from creating crown splashes to motion design water elements to pack shots with liquid exploding around them to realistic oceans to rain effects.Above render using our Water Splashes 2 PackWhy is this so hard? (Avoid joke here). Fluid sims are among the most complex tasks you will face. Why? Because fluid dynamics is a mathematical hellscape of complexity. If you go in too far, you will likely hear the term Navier-Stokes equations, which will immediately be followed by equations that look like maybe the alien language has been discovered.Graphic from this post.If you consider the properties youll be dealing with, then you will understand why the math behind the physics is so intense. Were talking about parameters like viscosity, flow, density, pressure, surface tension, turbulence, and vorticity. And this isnt even getting into lighting and texturing accurately! Fluids are REALLY tough. Because of this, you will be challenged with a daunting quest.What will you learn in this Fluid Guide?In this guide, youll learn the current landscape of tools and plugins you can use to achieve 3D fluid simulations. Youll learn which to use and which to avoid, and even discover some shortcuts you might consider along the way.Understanding Fluid Simulation BasicsThere are a few different types of fluid simulations. There are standard Liquid Simulations that simulate the behavior of liquids like water, oil, or lava. They often use methods like FLIP (Fluid-Implicit Particle) or SPH (Smoothed Particle Hydrodynamics).There are also Gas Simulations used for simulating smoke, fire, or gaseous-type phenomena. You can usually create these with Pyro effects. There are Particle-Based Simulations that use particle systems to represent fluids and let you create splashes, foam, and spray. There are also more specialized fluid simulations, like ocean and wave simulations. Lets first figure out what software is equipped to handle these best.Software recommendations for 3D Fluid SimulationSome 3D software handles fluids incredibly well, and some fail quite spectacularly. Lets start with the BEST, and proceed to the worst.The biggest takeaway for you is that if you want professional, top-shelf sims, then you have to learn Houdini. It is BY FAR the most capable, realistic, powerful, and accurate software for making simulations. The downside is that it has the steepest and most aggressive learning curve of all software!3D Fluids in HoudiniAbove render by Emmett MikitaHoudini specializes in multiple aspects of VFX, from modeling to final rendering. This software RULES film, television, advertising, and gaming industries by handling everything from rigging and animation to visual effects and lighting. It handles massive projects and crazy pipelines with no issues.Houdini uses the sophisticated FLIP (fluid-implicit particle) solver to give you both speed and precision in fluid simulations and creates realistic atmospheric effects, including mist, foam, spray, and bubble elements.Houdini also has Ocean FX tools for making seas, beaches, small oceans, large oceans, wave tanks, beach tanks, waves, and much more.Mastering Houdini requires significant time investment, but it can be well worth the effort when it comes to fluid simulations. Houdini is the leading solution for 3D fluid simulation in our industry.3D Fluids in 3DS MaxAbove render by Hammer Chen using Phoenix3ds Max boasts Chaos Phoenix, which is a powerful fluid dynamics system that can create various liquid effects, including bubbles, foam, and splashes.Phoenix is famous for making fire and smoke, but it has a fully featured fluid dynamics system as well. It works with the same principles as when it creates gaseous volumes and is unusual in that it works with voxels rather than particles, generating the surface at render time.Phoenix for 3ds Max and Maya can produce ship waves on the ocean, dribbling chocolate or frothing beer, and when rendered with global illumination using V-Ray, the results can be quite incredible!3D Fluids in MayaAbove render by BlendarianMayas Bifrost is capable of handling large-scale fluid simulations with tens of millions of particles. Bifrost is a procedural framework that can create simulated liquid and aerodynamic effects using a FLIP (fluid implicit particle) solver.The technology was employed as a dedicated tool for VFX studios and was used in films including Avatar, X-Men: First Class, and Rise of the Planet of the Apes.Its capable of handling tens of millions of particles for large-scale fluid simulations. It has the ability to produce fluid sims like foam particles, bubbles, spray effects, and rolling waves.3D Fluids in Unreal EngineAbove render by Jesse PitelaIf youre riding the Unreal train of real-time delight and you want to experiment with the watery world, they have their own built-in fluid simulation system for real-time fluid effects. Its called Niagara Fluids. It can be used to create complex fluid simulations for games and cinematics, including smoke, fire, and liquids.UE also has add-ons you can explore, like Fluid Flux, which is a third-party plugin available on the Epic Games Marketplace that offers real-time water simulation capabilities for rivers, oceans, and shorelines.3D Fluids in BlenderAbove render by CG GeekBlender has native tools for fluids that you can use without additional plugins or addons.It includes a system called Mantaflow, which lets you create various fluid effects. You can also dig into quite a few Blender add-ons for fluids, including FLIP Fluids, which is quite popular. Its a tool designed to help users set up, run, and render high-quality liquid simulation effects within Blender.TLDR, Blender has some great options for fluids!3D Fluids in Cinema 4dAbove render by Redila Media using PyroAnd now we come to the software many of us know and love, Cinema 4D. At this point, we wonder collectively why C4D is at the bottom of the list when I mentioned we would go from best to worst.Collectively we accept the reality: Cinema 4D kind of sucks at fluids.A handful of years ago, there was an exciting and enticing race to the top between X-Particles and Realflow. Sadly, X-Particles went off the rails with apparent corporate greed (not my opinion, but the opinion of all of the forums I have ever read), and Realflow mysteriously went inactive.This leaves us with the native C4D fluid tools. Oh wait, there are none. Crap.In Cinema 4D there are a few ways of approaching fluids that are AWESOME for motion design or static frames. They definitely are slow, and they dont look very good in many situations, but for certain applications, they work well. These include:1. Using C4D Pyro to generate the animation and then a volume mesher and builder to turn it into the required blobby geometry. This process allows for the creation of various fluid-like effects, including watery and slimy vibes.2. Using the 2024+ Cinema 4D Particle engine to create particle animations that are then fed into a volume mesher and builder to create the geometry. This method involves using emitters, field forces, turbulence, and friction to simulate fluid behavior. The particles can then be connected using a volume builder to create a fluid-like appearance. The downside is that its fairly slow to work with. Heck, I even made a tutorial on this process you can check out!3. Other dumb options: umm metaballs.Dont get me wrong; particles or pyro + volume builders are great ways to get by but most certainly wont generate anything with real-world perfection!The Ultimate Cheat CodeI have good news. Say you need a beautiful, photo-real, perfectly simulated fluid effect, and you open up the Houdini door and quickly shut it as the mathematical formulations tumble and gather at your feet.You go to door two; it has Cinema 4D in there, but its just not gonna get you to the finish line where the client triumphantly hands you the check.I would like to introduce a 3rd door. You open it and what do you find? Pre-simulated, pre-cached assets for all sorts of fluid effects that are pre-made with love just for you.This is the part of the blog where I shamelessly plug our Fluid Effects lineup of 3D assets in case you want bubbles, water splashes, crown splashes, rivers, and more. Weve done all the hard work (in Houdini of course) to make the perfect assets, which you can simply drag and drop into your next project. Theyre .abc Alembic files, so you can use them in any render engine or 3D app you want.With this shameless plug out of the way, lets talk about the future!Future of Fluid SimulationI dont have any insider knowledge about this, but I have heard rumors of C4D working on a fluid system behind the scenes, which makes a lot of sense because they recently introduced Pyro and Particles. Keep your eyes open for that.There are also other plugins in development, like LiquiGen, which are not quite perfect yet but are getting better all the time. And who knows what AI tools will come out with next?Currently, though, your choices are Houdini, 3ds Max + Phoenix, Maya + Bitfrost, Unreal Engine Niagara, or Blender.Or our assets, of course (which are better than anything you could dream of). Things change quickly, but for now, we are here at the end of this incredible journey.Conclusion and SummaryAbove render from The Pixel Lab Rivers PackI hope you have learned what you need from this overview, and youre ready to tackle the problems head-on. Whatever your client asks of you, I wish you the best of luck.Happy simulating, happy rendering, and Im here if you need anything. Good luck with your projects!Recommended Products
