Hey all,

Any reason we can't render with Storm or the HoudiniGL Hydra Delegates from the usdrender node?
Perhaps I'm missing something?

Cheers.

You can render Houdini GL from the regular OpenGL ROP, which is better suited for it (already has all the display options which are ignored by all other delegates).

Storm doesn't render using the AOV interface and it has GL dependencies, so I believe it wasn't included for those reasons.

This partially works for our use case: https://www.sidefx.com/forum/topic/71004/ [www.sidefx.com]

Would be good for Storm support in the future, and consolidating to the usdrender node.

Thanks for the answer above twod. That makes sense. Appreciate the response!

Cheers.

An interesting development with this seems to be that it doesn't support materials.

vochsel
An interesting development with this seems to be that it doesn't support materials.

This was fixed in 18.0.318. However, GL requires that you use a Principled shader or a USD Preview shader in order to see materials on GL objects.

twod

vochsel
An interesting development with this seems to be that it doesn't support materials.

This was fixed in 18.0.318. However, GL requires that you use a Principled shader or a USD Preview shader in order to see materials on GL objects.

is there a preview shader for volumes? There was a bunch of work done in 18 to improve parity between the pyro shader and the viewport visualizer. Will we see a Volume Preview shader for HoudiniGL eventually?

jsmack

twod

vochsel
An interesting development with this seems to be that it doesn't support materials.

This was fixed in 18.0.318. However, GL requires that you use a Principled shader or a USD Preview shader in order to see materials on GL objects.

is there a preview shader for volumes? There was a bunch of work done in 18 to improve parity between the pyro shader and the viewport visualizer. Will we see a Volume Preview shader for HoudiniGL eventually?

There's no preview shader for volumes, but lighting should use the same CL-accelerated codepath in LOPs as it does in SOPs. Volume shading has always been done by looking at the volvis attribs on the detail itself, which are pulled in by the import. I tested with the explosion shelf tool, and it looks the same in LOPs & SOPs.

twod

jsmack

twod

vochsel
An interesting development with this seems to be that it doesn't support materials.

This was fixed in 18.0.318. However, GL requires that you use a Principled shader or a USD Preview shader in order to see materials on GL objects.

is there a preview shader for volumes? There was a bunch of work done in 18 to improve parity between the pyro shader and the viewport visualizer. Will we see a Volume Preview shader for HoudiniGL eventually?

There's no preview shader for volumes, but lighting should use the same CL-accelerated codepath in LOPs as it does in SOPs. Volume shading has always been done by looking at the volvis attribs on the detail itself, which are pulled in by the import. I tested with the explosion shelf tool, and it looks the same in LOPs & SOPs.

So HoudiniGL is respecting volvis single value primvars (detail attributes)? (I haven't actually tried yet. I was hoping for a solution similar to principled shader crafting a preview surface)

Yes, it still uses the volvis attribs in lops (sops too). I'm not sure how a usd preview shader would map to a volume in a way that would be useful for visualization. The volvis attribs are pretty specific in function, which the usd preview shader doesn't come close to matching.

twod
Yes, it still uses the volvis attribs in lops (sops too). I'm not sure how a usd preview shader would map to a volume in a way that would be useful for visualization. The volvis attribs are pretty specific in function, which the usd preview shader doesn't come close to matching.

No, I wasn't picturing the USD Preview Shader being able to take on this capability, I was referring to the automatic creation of a gl-specific material when bringing a principled shader into USD that inherits its parameters. The benefit is that when modifying the parameters of the volume shader it affects the viewport visualization. I'm not sure how this would work in practice if the only way to control the visualization is with primvars. There could potentially be a ‘HoudiniPreviewVolume’ material, or a tool for writing the volvis primvars to the volume prims based on their assigned material.