What are the best tools and techniques for creating realistic fluid simulations in vfx?

1 Fluid simulation software

There are many software options for creating fluid simulations in vfx, each with its own advantages and disadvantages. Some of the most popular ones are Houdini, Maya, Blender, and RealFlow. These software tools use different methods to simulate the behavior of fluids, such as particle-based, grid-based, or hybrid systems. Depending on your project needs, budget, and preferences, you can choose the software that best suits your goals and workflow.

2 Fluid simulation parameters

One of the key aspects of creating realistic fluid simulations is to understand and adjust the parameters that control the fluid properties and dynamics. These parameters include density, viscosity, surface tension, pressure, temperature, gravity, and turbulence. By changing these parameters, you can create different types of fluids, such as water, oil, honey, lava, or gas. You can also animate these parameters over time to create variations and interactions between fluids.

3 Fluid simulation resolution

Another important factor that affects the realism and quality of fluid simulations is the resolution. Resolution refers to the number of elements or cells that the fluid simulation uses to represent the fluid volume. Higher resolution means more detail and accuracy, but also more computation time and memory usage. Lower resolution means less detail and accuracy, but also faster performance and less resource consumption. You need to find the optimal balance between resolution and efficiency for your fluid simulation.

4 Fluid simulation optimization

Optimizing your fluid simulation is essential to improve the speed and quality of your results. There are several techniques that you can use to optimize your fluid simulation, such as caching, meshing, substepping, adaptive resolution, and level of detail. Caching means saving the fluid simulation data to disk or memory for faster playback and rendering. Meshing means converting the fluid simulation data into a polygonal mesh for better visualization and export. Substepping means increasing the number of calculations per frame for more stability and accuracy. Adaptive resolution means adjusting the resolution based on the fluid motion and complexity. Level of detail means reducing the resolution or detail of the fluid simulation based on the distance from the camera or the importance of the scene.

5 Fluid simulation rendering

Rendering your fluid simulation is the final step to showcase your work and create stunning visuals. There are different rendering techniques and engines that you can use to render your fluid simulation, such as ray tracing, volume rendering, or shader-based rendering. These techniques use different methods to calculate the light, color, transparency, and reflection of the fluid surface and volume. Depending on your aesthetic and technical requirements, you can choose the rendering technique that best matches your vision and style.

6 Fluid simulation examples

To be inspired by the possibilities of fluid simulations in vfx, here are some incredible examples from artists and studios. You can watch the videos and learn their techniques and approaches to create realistic and artistic simulations. For instance, Igor Zanic's Waterfall video is available on Vimeo, as well as Allan McKay's Fire and Smoke, Scanline VFX's Blood, Igor Zanic's Lava, and Main Road Post's Gas.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?