Since 1.2.3, we’re getting a bunch of these for various shaders in Xcode:
Ambiguous path from opacity on node _XXX in graph USD_xxxShader. Choosing the first path.
What’s causing this? Should we be concerned?
I don’t think so; I’ve seen these as well, but I haven’t noticed any actual issues with rendered opacity. The messages come from Apple’s MaterialX reader, and it seems like simply having a Multiply node output to the opacity (alpha) is sufficient to trigger the message. I’ll report it to Apple.
Getting many of these too. It happens in some occasions when I plug a node into the opacity input of a surface. To me it has happened when using these nodes: clamp, smooth step, multiply, subtract, mix, range.
@AndrzejUnity Any comments from Apple?
No, I haven’t heard anything about this since reporting it. Is this causing issues with your shaders’ appearance, or are you just concerned about the warnings? Either way, you can report it to Apple using Feedback Assistant, and optionally reference our submission about it, FB13775497.
Thank you. We have not seen any render issue or performance issue. It seems to be benign.