Dragging a Blender imported model into a Stage doesn't show any materials

Omniverse Developer Tools & Resources Samples & Examples
1

If I drag a Blender model I used the Export USD button to generate into a Stage, it’s 100% grey.

However, I created a new Layer on that model, and if I import the USD representing that layer, only the materials changed in that layer show up, the rest is still grey:

Screenshot 2023-09-26 175332
Screenshot 2023-09-26 1753321445×1026 90.8 KB

What’s going on here?

2

Not sure I have all the details. Let me ask some questions.

  1. You are using the official Blender OV connector to export a blender model as a usd ?
  2. Rather than dragging and dropping into a new file, please just OPEN the usd directly
  3. You assigned materials in Blender that are not showing up in Composer ?
  4. " I created a new Layer on that model, and imported the USD representing that layer" ???
3
  1. Yes
  2. That works, but several videos from Nvidia shows how easy it is to drag USD files into scenes…
  3. No, I assign materials in a new layer in Composer, which then doesn’t show up in Composer if I drag the USD into s scene.
  4. Yes. When you create a new Layer in Composer, apparently you also create a new USD file. The screenshot is from dragging that USD file into a new scene. If I’d dragged the original USD file instead, it would be 100% grey.
4

Ok thanks. Yes you can drag and drop USD files into other scenes, but any time you are having issues it is good to just open the base file normally to start with.
You are assigning materials using a new layer. That is not wrong but is there a reason you are not just replacing materials in the root layer ? The issue is that, yes a new layer creates a new usd which must be loaded over the base usd file to work correctly. Then you have two files to think about when dragging the scene into a fresh file. You would have to bring in the model.usd and the materials.usd for it to work correctly.

5

I was also very surprised that a layer is its own file. That wasn’t made apparent in the marketing videos, but what was made a selling point, and one which convinced us, was the non-destructive workflow, so I thought that assigning materails also as a layer would be nice to be able to refer back to how the file originally was. Or should I have made a layer override? I heard it called an “opinion” which I found hilarious, but haven’t looked too closely at that yet.

6

Yes the non destructive workflow through layers is really amazing.

7

I tried to drag the above model into a new Stage and noticed several hundred lines with very similar text:

2023-10-03 09:01:07 [Warning] [omni.usd] Warning (secondary thread): in _ReportErrors at line 2890 of W:\ac88d7d902b57417\USD\pxr\usd\usd\stage.cpp – In </World/Ferry_2023_Standalone/_Main_Assy/____Ship_Common_Systems/____Ship_Common_Systems_2/_9___ELECTRIC_CONSUMER_SYSTEMS/_93_ELECTRIC_LIGHTING_SYSTEMS/_93_001_GENERAL_LIGHTNING/LED_STRIP_EXTRUSION_17/LED_STRIP_EXTRUSION_body1_17/LED_STRIP_EXTRUSION_body1_001.material:binding>: The relationship target </Materials/color_9ca8abff_004> from </root/_Main_Assy/____Ship_Common_Systems/____Ship_Common_Systems_2/_9___ELECTRIC_CONSUMER_SYSTEMS/_93_ELECTRIC_LIGHTING_SYSTEMS/_93_001_GENERAL_LIGHTNING/LED_STRIP_EXTRUSION_17/LED_STRIP_EXTRUSION_body1_17/LED_STRIP_EXTRUSION_body1_001.material:binding> in layer @C:/Users/Robert/Documents/Omniverse Projects/Ferry 2023/Ferry 2023 Standalone Omniverse Materials.usd@ refers to a path outside the scope of the payload from </World/Ferry_2023_Standalone>. Ignoring. (getting targets for relationship </World/Ferry_2023_Standalone/_Main_Assy/____Ship_Common_Systems/____Ship_Common_Systems_2/_9___ELECTRIC_CONSUMER_SYSTEMS/_93_ELECTRIC_LIGHTING_SYSTEMS/_93_001_GENERAL_LIGHTNING/LED_STRIP_EXTRUSION_17/LED_STRIP_EXTRUSION_body1_17/LED_STRIP_EXTRUSION_body1_001.material:binding> on stage @C:/Users/Robert/Documents/Omniverse Projects/Ferry 2023/Ferry 2023 Open Seas.usd@ <0000025EDC1AE640>)

I thought I did everything correct when making a new layer, but apparently you’re not supposed to use the option from that popup I chose… I’m not sure that popup then is good to put in front of a new user without a link to documentation that really explains the consequences…

Screenshot 2023-10-03 112020

The trouble is, though, even though I flattened the sublayer and the original file looks fine, I still get all of those messages and wrong materials every time I open a USD file with that file linked in it…