looking for Karma XPU shading&rendering tutorial

[tagosaku]

Hi, I am trying to render my water elements with XPU rendering in Solaris, then looking for a sort of sidefx's materclass. So far, I have found:

 

Karma XPU can be faster than Karma CPU 10%-35%.  

Karma XPU must use either XPU shader, MaterialX, and not available with  VEX shader(default/regular/classic shader) that make me very difficult!

 

Thus, specific question can be: 

1 Mesh geo probably uses 'mtlxstandard_surface', in stead of principled shader. However, how do we bind each attribute data, like Cd, rest,? And there is no uv slot on the material, then how to apply texture, too?

 

2 I think PyroShader+XPU_Pyro_Preview_shader+Collect nodes are probably standard way to use as volume shader, and not sure how to add/create the specular on volume using normal/gradient VDB? For instance, we can create such a fake specular by PBR reflection, but should not be available that node for Karma XPU.

 

3 Now Karma XPU can apply ocean displacement by using Houdini_Procedural_Ocean node. Even we have example files from Ocean shelf, small and large Oceans. However, I am not sure how exactly particles use in that subnetwork, also how it respects a geometry's rest or UVs.   

 

4 In general, how do we input/bind attributes and how to export AOVs in Materials? Do we have a page to learn such fundamental rules? Even volumes, it seems to rename from vel to velocities to use mtlx?? So confusing!!   (I think Arnold and Redshift shaders are much simpler and smarter!! )

 

5 which choice is better performance to render Karma XPU, either kma_shaders or mtlx_shaders?

 

6 According to Display options Solaris > Guides > Additional information > Render Stats ON, Karma XPU only uses 'Device 0, EmbreeCPU' , not using my GPU-videocard. I don't know why Karma does not access to GPU. device. 

About Houdini 20.5shows;
Windows 10 Pro
OpenGL Vendor:            NVIDIA Corporation
OpenGL Renderer:          NVIDIA GeForce RTX 3060/PCIe/SSE2
OpenGL Version:           4.6.0 NVIDIA 526.98
OpenGL Shading Language:  4.60 NVIDIA
Detected:                 NVidia Consumer
                          12288 MB
                          526.98.0.0

so at least, Houdini understands my PC has nvidia GPU device....

 

After all, it turns out very long questions, but it really appriciates if you can answer a tip for one of them, or useful links. Thanks in advance!!!!!!

 

Edited September 21 by tagosaku

[tagosaku]

There is an answer. To use camera motion blur, we have to create a cache node after a scene import cameras node in Solaris!! And set parameter cache BEhavior > Always Cache All Frames!! Of course, set Karma Render Settings > Renderingtab > Camera Effects tab > MotionBLur check box ON.