Introduction to Houdini: Fluids

Simulating Fluid Interactions with David Silberbauer

David Silberbauer teaches how to create a simple fluid-interaction shot of sharks in an ocean in this new 4.5-hour workshop. He begins with warm-up exercises that show how to set up simple fluid scenes using Houdini’s built-in shelf tools. These introductory lessons offer a fun way for aspiring Houdini artists to become familiar with FLIP fluids and understand the differences between DOP and SOP setups. While these setups are fundamentally the same under the hood, understanding how they work is critical when setting up shots.

Moving into white-water setups, David continues to demonstrate the differences between DOP and SOP workflows, explaining why artists would choose one over the other. From there, building on the experiences learned, he jumps into shot work, starting with bringing in a shark animation before setting up a basic ocean tank. His setup does most of the heavy lifting, connecting nodes, channel referencing, and adding default settings that work well out of the box. He talks through all the key settings so artists can adjust them as needed to achieve the right look.

From there, artists are ready to start the first FLIP simulation using the shark animation in the ocean tank. David explains why it’s always a good idea to have this simulation dialed in just right, since it will form the basis for other elements of the effect. With the sim setup in place, David then leads the build-out of a white-water system to mesh the fluids. He demonstrates how to extend the ocean using the ocean spectrum and how to smoothly blend between the ocean spectrum and the FLIP simulation using volume masks. 

In the final stage, he shows how to bring in all the elements and assemble them in Houdini Solaris. He also walks through creating materials for the shark* and the featured Poly Haven assets**. David discusses how to inspect the Houdini ocean procedurals and adapt them to control the water's appearance. With the technical work completed, it’s then time for artists to tap into the creative right side of the brain, learning how to set up two basic day and night lighting setups. His workflow wraps up with adjustments to the Karma render settings to achieve an optimal final render.

*The Shark model featured in this workshop and available to download as a project file is courtesy of the Digital Life Project at UMASS Amherst (Digital Life) and the University of Massachusetts at Amherst (www.umass.edu).

**The following Poly Haven assets were used by David to assist with adding scale to the environment: Modular Wooden Pier, Metal Trash Can, Wooden Bucket, and Hanging Industrial Lamp.