Hello,

I created an HDA for helping asset look-dev rendering standardization. One of this HDAs contains a set of light rigs that users can easily switch with a simple ordered menu parameter. Some of this lights require an HDRI textures in the form of embedded EXR files in the HDA itself and accessed in the lights "texture" parameter via the "opdef:" syntax. This was working fine and dandy in Karma (CPU and XPU) within Houdini 19.0 in all situations, rendering in "viewport" as well as rendering to disk via "usdrender_rop" but, once I started using Houdini 19.5, Karma seems to not be able to resolve those paths when rendering via "usd render rop" and only seems to work on the viewport (?)

Attaching a HIP file with an embedded HDA that contains an EXR file and a light referencing it.

At file open, go to "Stage", make sure the display flag is set on "karmarendersettings" operator and set the viewport renderer to Karma and you'll see the HDRI file is found and renders fine but, if instead one selects the "usdrender_rop" and hits render to disk, the HDRI texture won't be loaded. I noticed that, when Karma is set to XPU. I get no warnings whatsoever but when set to CPU a warning pops up in the console window stating:

" Unable to load texture 'opdef:/Lop/opdef_light_tex::1.0?alps_field_1k.exr'"

Is this a new known limitation? A bug? or ... ?

Thank you!

Is the hda in the Houdini HDA search path, or was it installed to the Hip file? I can see it not being found by husk if it was the latter since I don't think husk has otload commands like mantra.

Hey jsmack,

You're right, on this particular example turns out that it won't work because the HDA is embedded in the HIP, therefore Husk/Karma can't find it... learned about this after I posted (!)

Unfortunately, in 19.5.303 even if the HDA is external and present in any OTL scan folder, Husk/Karma is not able to find the embedded map, but same exact setup in 19.0.657 worked just fine.

I went back and forth with SideFX support and they where finally able to find the problem. I've been told the issue was related to OpenImageIO being confused about the file type extension, the fix should be available in 19.5.340(!)

Thank you for checking!

This problem seems to persist in Houdini 19.5.368.