Hey all,

Just wondering if the following is supported yet in Karma XPU or if I'm doing something wrong?
(Running Houdini 19.0.445)

I'm using the Instancer LOP in Point Instancer mode to instance geometry to some points, those points have an attribute I'm using as the UV coordinate for a texture I'm applying across the instances.

I can see my primvar attribute in the scene graph details correctly, when inspecting the instancer. I'm using the MtlX USD Primvar Reader to read the attribute and use that as the texcord for the MtlX Image nodes.

The Karama CPU result looks correct, but when switching to XPU I get a constant value of 0,0 and is obviously not working.

Happy to accept this is a limitation of the Alpha but if there is a workaround any help would be greatly apricated!

Thanks,
John

Looking through the XPU docs sounds like this is just un-supported for now, but I did find a interesting mention of being about to use the mtxl dot note and call functions like ray:hitP

This one is of particular interest as it appears to be some kind of camera space position mapping that I might be able to hijack for my render.. But I can't find any information on what ray:hitP is, does anyone have a definition of this function?

EDIT: it appears to be just world position, same result can be achieved with MtlX Position set to "world", this function works on instanced geo rendered with XPU