Hi, i’m able to load USD on the stage in 4.25.2 and have it’s animation sequence play correctly.
My issue is that either the USD unloads when switching level (or when loading the USD actor inside a sublevel) OR if i do a full USD import, the animation sequence reference breaks and i can no longer playback the animation! Neither of these are workable for a real filmmaking project, only to preview that the USD system will import our data.
Long explanation: Loading on stage - When the USD is opened on the stage, it appears in the unreal level and can be setup with materials etc. The problem comes when changing to other levels, or when opening it as a sublevel in another level, The mesh is simply not there. Reloading the stage fixes this but it loses all references so it’s ‘naked’ without materials again. booo! I want to be able to setup the USD one time and load it as a sublevel in other levels im using for filmmaking.
**Import as assets - **The second option is to Import the USD as permanent unreal assets, effectively copyng the USD into the project. However this breaks the animation stored in the level sequence of the USD. Since that level sequence isn’t a selectable asset (it lives in the invisible /Engine/Transient folder apparently) we dont have a way of getting it attached to the newly imported geometry, or to repair the link and get the animation playing again.
After importing the whole USD as uassets, the level sequence is still stuck on this engine transient version of the sequenece, but no longer will play?
I found out in sequencer you can play back animation by animation the time track on a USD Stage Actor, but I was expecting that USd would just animate out the box. I want to clarify that I’m using point deformed animation in my USD. I 4.26 I found that I can animate individual elements on a USD stage using the Geometry cache track. Both methods require at least two keyframes, I figured the workflow would be slightly easier, similar to dropping FBX tracks in Sequencer. Is it possible any devs can clarify this workflow?
For point 2 to the OP, you can create a sublayer in the stage editor layers section, make it the editable layer by right clicking and edit. then you can assign materials to the prims. If you save the layer any changes (transforms, shading, etc.) will now be overrides in that layer. The next time you open the stage in any software, specifically UE, the shading will now be reapplied.
Once you’ve done it once, you can open the the file, preferably saved as usda, into your favorite text editor and it’s kind of neat, because you can see the materials get saved as paths to the location in you content browser on the prims.
If I bring in a Static character (from maya2020) as USD stage into Unreal 4.26, I would get all the materials / textures.
Instead if I bring in the same character with animation, I am able to get the animation working in Unreal, but I would
get No textures.
I guess this is because Animated meshes in USD stage do have UVs, but some how these UVs cannot be read by
Unreal. May be as these UVs are animated mesh values.
