How to Use Volume and COPs to create Wet Maps

Yongji Chen shows a better and faster way to develop wet maps in Houdini.

A new tutorial (and his first) from Yongji Chen covers a faster and more efficient way to create wet maps in Side FX Houdini. “Compare to traditional workflow, it is much faster and gets a better result,” Chen says. Typical workflow for creating these types of maps involves subdividing geometry quite a lot to accommodate the object collisions correctly or at sufficient resolution.

All that geometry doesn’t make the work more efficient. “The points on surfaces are unevenly scatted. That is a very inflexible and heavy workflow,” Yongji notes.

Yongji’s method works out to be much lighter and allows you to set the texture size to anything. “I did a comparison in the video, to get a similar result, my new workflow is almost 9 times faster than the old one.

And since it’s a texture sequence, it’s also beneficial for game artists to bring them into game engines.” Yongji makes the project files available for a small fee – for those people who want to know how to apply this workflow on objects with UDIM tiles. You can download it from

Other techniques are just as relevant, so check out CG Generalist Tim van Helsdingen’s tutorial on how to create wet maps using a CHOPs network in Houdini.

Or how to create a UV-based wetmap with this tutorial from FX TD Fabricio Chamon.