Trying to tackle PBR ocean lookdev within karma, I'm not able to replicate the VEX Builder workflow within mtlx/karma builder. The Ocean sample layer is not available, I can bring it in via copy paste from a VEX context but this already tells me it's not going to work. Pluging it to the dsp input does nothing then, both in karma and mtlx builder context.

What would be the best way - while remaining fully in LOP context without SOP import - to bring in a bgeo spectrum and apply it as DSP in karma/mtlX ? My best take is baking displacement to maps, which is a viable solution but since the spectrum cached bgeo also contains other useful data, I'd be keen on using it rather than baking everything onto the mesh (cusp, vorticity, whitewater etc..)

Bumping this in case some master mind happens to swing by...!

I don’t know enough to give you a really good answer but since no-one else has answered in months I will chime in.

Vex will not work at all with Karma XPU/MaterialX.

I am not clear on why you don’t use the built in houdinioceanprocedural, but if you want to roll your own you might try diving into it down through the nodes until you get to the mtlxstandardsurface that shades the ocean. There may be something there you can use.

The ocean procedural is the way forward since it solves for a render agnostic workflow rather than something rolled for karma. It's also operating as a compiled sop graph at render time which makes it fast to evaluate and predictable to debug (since you can have husk spot out the rendered mesh if needed for debugging). If you need something custom you'd be better off trying to make your own procedural version than looking for a shader solution