Distortion Artifacts on VisionOS When Rendering Opaque/Alpha Clipped Foliage in URP (Unity 6.0, Metal)

I'm running into a persistent visual issue while deploying a floral corridor scene to Apple Vision Pro using Unity 6.0 with URP and Metal. The issue only appears on the Vision Pro device — everything looks fine in the Unity Editor.

Issue Description

When the frame rate drops to around 60–70 FPS, noticeable distortion artifacts appear around the edges of foliage models. It seems like the background meshes (behind the plants) get warped and leak through the edges of the foliage. Although this is most visible around the leaves, even solid objects like standard URP wall or box models show distorted edges when the issue occurs.

All the foliage uses Opaque or Alpha Clipping materials.

Things I've Tried

1. Changing the foliage materials to Transparent mode —distortion around edges disappears, but using Transparent for a large number of foliage assets is not ideal for performance or sorting complexity.
2. Reducing the number of foliage objects — with only a few plants in the scene and the frame rate staying around 100 FPS, the distortion disappears. However, this isn’t a practical solution for a full environment.

Possible Cause?

I came across this note in the Unity documentation: "Ensure depth-buffer for each pixel is non-zero - on visionOS, the depth buffer is used for reprojection. To ensure visual effects like skyboxes and shaders are displayed beautifully, ensure that some value is written to the depth for each pixel." Could this be related to the issue? Is it possible that Alpha Clipping with low pixel coverage leads to some pixels not writing to the depth buffer, which then causes problems during Vision Pro’s reprojection or foveated rendering? However, even when I disable Alpha Clipping entirely, the distortion issue still persists, so it may not be solely caused by clipping itself.

Project Setup

Unity 6.0 (URP)

Depth Texture: Enable

Using Metal as the graphics backend

Running on real Vision Pro hardware (not simulator)

Any advice on how to avoid these distortion issues on Vision Pro would be greatly appreciated. Thanks!