Kit 106.4.0 - Fabric Scene Delegate - USDRT - How to correctly enable it

Omniverse Core Platform Kit SDK
1

Hello,

I am trying to use one of my extensions (Python) that uses Fabric Scene Delegate in a new Kit app (106.4.0), but it just won’t work. No errors or any other log level. I backed to try the Kit Base Editor 106.4.0 .kit profile, but nothing. The extension USDRT SCENEGRAPH API (usdrt.scenegraph) is enabled. I affixed the settings in .kit to “app.useFabricSceneDelegate = true”.

To test I am running the first basic example script from Authoring geometry with USDRT and rendering with Fabric Scene Delegate — USDRT 7.5.0 documentation and of course, zooming in.

import omni.usd
from usdrt import Usd, Sdf, UsdGeom, Rt, Gf, Vt

stage_id = omni.usd.get_context().get_stage_id()

stage = Usd.Stage.Attach(stage_id)

prim = stage.DefinePrim("/World/Triangle", "Mesh")
mesh = UsdGeom.Mesh(prim)

points = mesh.CreatePointsAttr()
points.Set(Vt.Vec3fArray([Gf.Vec3f(1.0, 0, 0), Gf.Vec3f(0, 1.0, 0), Gf.Vec3f(-1.0, 0, 0)]))
face_vc = mesh.CreateFaceVertexCountsAttr()
face_vc.Set(Vt.IntArray([3]))
face_vi = mesh.CreateFaceVertexIndicesAttr()
face_vi.Set(Vt.IntArray([0, 1, 2]))

rtbound = Rt.Boundable(prim)
world_ext = rtbound.CreateWorldExtentAttr()
world_ext.Set(Gf.Range3d(Gf.Vec3d(-1.0, 0, -1.0), Gf.Vec3d(1.0, 1.0, 1.0)))

It does work on Composer 2023.2.5 Beta.

Please, what am I missing here? Thanks

Also, it would be nice to have here tags for Fabric, Fabric Scene Delegate, and USDRT. It’s difficult to find certain topics on these subjects.

2

Ah, I remember this one :-) This came up before and it turns out it was working fine, but the triangle was TINY and you literally have to find it at the center of 0,0,0 or better still just really really zoom in. If it shows up in the stage tree just click that name and then hit “F” to find it and zoom in, in the viewport.

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3

“You are correct! I did have to zoom way in and it was even mostly covered by the default light in the new stage scene but it is there! Thank you so much for taking the time and pointing that out. I’ll get back to that story :-)
In my noob-ness I am also not well-versed in navigating viewports with mouse and keystrokes, scroll/zoom speed,etc so that probably also contributed to my difficulty with this.”

Authoring Geometry for Fabric Scene Delegate Not Working - Omniverse / General Discussion - NVIDIA Developer Forums

4

Hi Richard, thanks! But, well, unfortunately it’s not the zoom issue. I had that too! Solved because of your old topic, thanks again. In fact there is nothing on the tree either. It is working in Compose with old Kit (105) though! But Compose has too many dependencies/extensions and I can’t find what I am missing.

5

Ah ok. That makes sense. It must be an issue with the new Kit App Template. What exact version are you using? What dependencies are you missing? If you are getting errors even before you start, please let us know exactly.

I will have the engineers follow this tutorial in the new KAT and make sure it is supposed to work. Sorry about that.