Creating a Dynamic Wet Map Shader in Houdini
This tutorial introduces a new method for simulating wet objects, a shader-based method that first generates a 3D cloud of animated wet points, then by creating a shader that will use this data to shade the wet, previously-wet, or drying parts of the character that were previously in contact with a fluid. Software required: Houdini 14.
What you'll learn
To realistically simulate fluids (water, blood, paint, oil, etc.), often a wet map is required to change the shading of an object where the fluid comes into contact with an object. These need to animate, not only while the fluid is active, but also afterwards to simulate drying. The usual solution, generating a wet map, or fixed set of images for a texture map, has several drawbacks: fixed resolution, color depths, and difficulties applying across objects or to subsequent shots in the film. This tutorial introduces a new method for simulating wet objects, a shader-based method that first generates a 3D cloud of animated wet points, then by creating a shader that will use this data to shade the wet, previously-wet, or drying parts of the character that were previously in contact with a fluid. This will be accomplished without any need to create or rerun the original fluid simulation. Software required: Houdini 14.
Table of contents
- Setting up the Paint Splash 10m
- Forming Paint-splash Fluid and Wet Points 11m
- Paint Splash Wetness Transfer 12m
- Creating the Wet Map Points Point Cloud 5m
- Constructing the Wet Shader 7m
- Finishing the Shader 12m
- Floating the Innertube 10m
- Setting up the Innertube Fluid Simulation 9m
- Creating Wet Map Points and a Wet Shader 10m
- Finalizing the Float Tube 7m
- Zombie and Blood 7m
- Setting up the Blood 9m
- Simulating the Blood 10m
- Finalizing the Blood Hit 5m
- Creating Wet Map Points on Animated Geometry 10m
- Zombie Blood Hit Final Render 3m
About the author
Jeff Wolverton has been working on visual effects for major motion pictures for over 15 years, having created signature effects for Sony Pictures Imageworks, Digital Domain, Rythym & Hues, Framestore, MPC, Disney, and Dreamworks. He specializes in unique and unusual procedural effects, as well as the standards (fire, water, smoke, destruction, dust, fluids and atmospheric effects). He was also the screenwriter for the Academy Award-winning animated short, The ChubbChubbs!