Bug 258063

Summary:	Some gltf models not rendering properly on Mac Intel when using WebGL via Metal
Product:	WebKit	Reporter:	Tom Felder <tom.felder>
Component:	WebXR	Assignee:	Nobody <webkit-unassigned>
Status:	NEW ---
Severity:	Normal	CC:	webkit-bug-importer
Priority:	P2	Keywords:	InRadar
Version:	Safari 16
Hardware:	Mac (Intel)
OS:	macOS 13

Description Tom Felder 2023-06-13 23:19:01 PDT

Some 3D models show obvious artefacts (texture flickering) when rendered in Safari on MacOS. This does not happen with BabylonJS. It might be related to the environment map. If one disables it, e.g. on Don McCurdy's viewer (https://gltf-viewer.donmccurdy.com/), the problem disappears. It only happens on Safari on MacOS when "WebGL via Metal" is enabled in Experimental Features (default setting). It seems that the issue happens only with Intel Macs.

Reproduction steps
1) Open Safari 16.5 ("WebGL via Metal" needs to be enabled in "Develop">>"Experimental Features") on Mac OS Ventura 13.4 (Processor: 2.3 GHz 8-Core Intel Core i9, Graphics: Intel UHD Graphics 630 1536 MB, Memory: 16 GB 2667 MHz DDR4)
2) Go on model viewer main page: https://modelviewer.dev/
3) See flickering on astronaut model

This happens for different models in different gltf viewers (also on Don McCurdy's viewer), but the most obvious was to show the example on the model viewer homepage

Comment 1 Radar WebKit Bug Importer 2023-06-20 23:19:37 PDT

<rdar://problem/111083533>