Simulation in Houdini - Saved by the Whale, Part 1

Taught by Ganesh Lakshmigandan
Duration:
4 hours 10 minutes
Software Version:
20.5 
Launch Date:
December 2024 
Course Number:
HOU238
3D
vfx
Part one of this production-centric workshop focuses on creating the simulation aspect of a medium close-up water scene featuring a character and a whale emerging from the water. Taught by Ganesh Lakshmigandan, he shares production-proven techniques gleaned from working on high-end projects such as Avatar 2, upon which the scene for this course was inspired by.

Using Houdini's SOP-level FLIP solver alongside the traditional DOP FLIP solver, members will learn how to craft a realistic and a relatively calm water simulation. The course also covers essential details like hair-water interaction, dripping fluids on the character and whale, foam simulation and projection, wet maps, and droplets on the character’s surface, ensuring a highly believable and visually engaging result.

Lakshmigandan is a senior FX artist whose credits include Avatar: Fire and Ash, House of the Dragon: Season 2, Avatar: The Way of Water, Dune: Part One, The Jungle Book, and Dunkirk. When he’s not doodling in Houdini, Ganesh pursues his passion for street photography, capturing the essence of everyday life through his lens. Follow his journey on Instagram: @g.lakshmigandan.
 

Class Listing

Class 1: Spectrum and Low-Resolution Bulk Simulation

We’ll start with a basic overview of the various water elements we’ll be creating, along with a structured plan for the order in which these elements will be simulated.
We’ll begin with a walkthrough of the sbw_start scene file. Starting with a spectrum setup, we’ll move on to setting up a low-resolution bulk simulation, laying the foundation for our shot.

Class 2: Low-Resolution Bulk Simulation, Continued

We’ll refine our low-resolution bulk simulation by adding the spectrum, setting up collisions, and incorporating custom forces around the character to achieve more dynamic and interesting behaviors.

Class 3: Hair Simulation

This class explores ways to simulate hair-water interaction using the Vellum solver. Additionally, we’ll work with the hair-gen node to tweak the final groom, enhancing the look of the simulated hair post-simulation.

Class 4: Dripping Fluids (Character & Whale)

Building on our low-resolution bulk simulation, we’ll emit dripping fluids from the character’s hair and body. We’ll discuss critical aspects like fluid sourcing, collisions, viscosity, and surface tension to ensure believable dripping behavior. Once the setup is finalized for the character, we’ll adapt the same setup with minor modifications for the whale.

Class 5: High-Resolution Bulk Simulation, Final Fluid Surfacing, and Ocean Extension

In this class, we’ll rerun the bulk simulation with higher particle separation for greater detail. We’ll also integrate the cached dripping fluids to create pseudo-interactions with the high-resolution bulk simulation. Finally, we’ll surface the high-resolution bulk sim, extend the ocean, and surface the dripping fluids for a polished final look.

Class 6: Wet Maps, Droplets, and Foam Simulation & Projection

In the final chapter, we’ll focus on SOP-based wet map generation. Using these wet maps, we’ll generate droplets on the character to enhance the wetness effect. The class will conclude with foam generation and projection to complete the water simulation.