Hey sesi,

I was wondering if there were plans to release any shading examples that call upon and illustrate the different shading paradigm available under the pbr umbrella. Right now all of the shaders that ship with houdini wrap the phong lighting model around the newly available bsdf approach - it would be nice to have a shading example that discards that lighting model (spec, diffuse, etc) in favour of a more legitimate physical description of the surface. There's a lot of information bouncing around out there regarding the new bsdf description in houdini but most of it concentrates on using it to interpret the phong lighting model. I've got my own ideas (as I'm sure that many of us here do) but I'd like to see an implementation from you guys that I can use as a comparison. Thoughts?

I know you guys are there, I can hear you breathing.

The vex surface context has quite a few physically based lighting models exposed. They are all documented in the help along with a page on “Writing VEX shaders for physically based rendering (PBR)”.

http://localhost:48626/vex/pbr [localhost]

That page contains several of the available primitive BSDF functions: phong, phonglobe, ashikhmin, blinn, matchvex_blinn, specular, matchvex_specular, cone, wireblinn (good for hair), wirediffuse (diffuse for hair),


In vops, you can access some of these lighting models in the lighting model vop.

The shipping materials with H9 purposely separate diffuse contribution from specular contribution for raytraced, micropolygon and pbr renders. I believe there are no purpose built pbr materials available in the gallery.