Found problems in the export of Reality scene(s) to USDZ

RC2usdz_issues.md

Issues with the Preliminary RealityComposer Scene Export as USDZ

I have encountered the following 5 issues in scenes exported with the following versions / creator strings:

• "com.apple.RCFoundation Version 1.4 (134.6.1)" (found on the web)
• "com.apple.RCFoundation Version 1.4 (133.20)" (RC export on my macBook)

Issue 1: sceneGroundPlane

reported as FB7660346

Found:

There is a Mesh named "sceneGroundPlane" without any vertex data and properties for normal and position instead of a usual XForm transform.

def Mesh "sceneGroundPlane" (
    customData = {
    		bool preliminary_isSceneGroundPlane = 1
    }
)
{
    rel material:binding = </Root/Scenes/Scene/sceneGroundPlane/physicsMaterial>
    float3 normal = (0, 1, 0)
    float3 position = (0, 0, 0)
    rel preliminary:physics:collider:convexShape = </Root/Scenes/Scene/sceneGroundPlane>

    def Material "physicsMaterial"
    {
        double preliminary:physics:material:friction:dynamic = 0.58
        double preliminary:physics:material:friction:static = 0.58
        double preliminary:physics:material:restitution = 0.48
    }
}

Expected:

I would have expected either a Mesh with vertex data and Xform properties or an all new type/kind of Prim instead of a Mesh.

Issue 2: Export does not warn when more than one scene uses HorizontalPlane Anchor

see FB7660332

Issue 3: Scene Name Property

In RealityComposer we can give a scene both a name and a description. But the USD exports only its name, but trice:

• first the XForm is named "Scene_2",
• second there is a property sceneName
• and third a similar property below customData

reported as FB7660341

Found:

        def Xform "Scene_2" (
            customData = {
                bool preliminary_collidesWithEnvironment = 0
                string sceneName = "Scene 2"
            }
            sceneName = "Scene 2"
        )
	{ ... }

Expected:

        def Xform "Scene_2" (
            customData = {
                bool preliminary_collidesWithEnvironment = 0
                string sceneName = "Scene 2"
                string sceneDescription = "Details for scene 2"
            }
        )
	{ ... }

Issue 4: Materials and surfaces are exported twice

seems to be causes by another problem - not reported in Feedback Assistant

Found:

Materials are exported in Scope "Geom" before the vertex data as well as in Scope "Materials" again.

Expected:

I would expect to find them in only one of the scopes. Typically in "Materials".

Issue 5: Accessibility help is not exported for Behaviours

FB7660363

Expected:

Both the bool to show a hint as well as the hint text for a behaviour itself should be exported and later also used in ARQuicklook.