GafferCycles does not handle textures within USDZ scenes

[andrewkaufman]

Version: Gaffer 1.4.6.0-linux-gcc11
Third-party tools: Cycles (from the Gaffer distro)

Description

I am testing USDZ support in various DCCs. @murraystevenson let me know that GafferCycles can render UsdPreviewSurface shader networks now 🥳, so I've included it in my testing. It works great on my test data after I unzip to .usda/.usdc, but on the .usdz directly the textures don't render 😿

This test data includes a driven file input, where inputs:file of the UsdUVTexture is driven by an input on the UsdShade.Material. I mention this because you'd be surprised how many DCCs failed this additional connection test so far, so good work!

ShaderTweaks is able to locate the correct texture files within the USDZ, so I believe its a GafferCycles bug rather than a GafferScene bug.

Steps to reproduce

1. Download https://drive.google.com/file/d/1qUHkOrtXG55vjtSAMl-i0qhnykPgezqr/view
2. unzip .usdz to produce the .usda data & textures alongside it
3. Load https://gist.github.com/andrewkaufman/d058b88884ac576a45f602af59f46786
4. Fix the SceneReader paths if necessary (they are loading from $HOME/Downloads/ so it might just work already)
5. View Parent node
6. Enable Cycles with Full shading in the viewport and expand all
7. Change Switch index to view USDA render
8. Enable each ShaderTweaks & rewire as needed to verify screenshots below

Evidence

GafferCycles with USDZ via SceneReader:

GafferCycles with USDA via SceneReader (same data but unzipped on commandline first):

ShaderTweaks can locate the texture within USDZ (that string path was prefilled when I added the tweak, I did not edit the path manually):

ShaderTweaks to the unzipped texture fixes the USDZ render: