SceneViewer has glitchy opaque/transparent sorting order

[hybridherbst]

Description

Related to #1065 but for SceneViewer.
The model has issues with the ground plane shadow, and additionally a lot of sorting order / transparency glitches (much more broken in SceneViewer than model-viewer and definitely much much more than directly in SketchFab).

SceneViewer (same happens in AR):

Sketchfab "Ground Truth":

Note: we actually found this issue while on a client project with a different model, but the model below is similar in broken behavior.

Live Demo

https://glitch.com/edit/#!/wax-citrine-cress

Browser Affected

• Chrome
• Edge
• Firefox
• Helios
• IE
• Safari

OS

• Android
• iOS
• Linux
• MacOS
• Windows

Versions

latest

[cdata]

This looks like it might just be z-fighting with the shadow plane. WDYT @elalish ?

Sorry, I totally missed that this was Scene Viewer 😅

cc @tpsiaki

[hybridherbst]

Yeah, the other one I opened is for model-viewer (where similar stuff happens plus the floor object is totally missing - thought it makes sense to open separate issues for those): #1065