There is a way to do this, but you will need to create a simple Shader Graph material instead of using the default OcclusionMaterial. There is a second version of this node called ShadowReceivingOcclusionSurface I didn't test this with Grounding Shadows, but it works with regular dynamic light shadows. You can find my notes on this from last year. https://stepinto.vision/labs/lab-026-using-dynamic-lights-and-shadows-with-passthrough/
Topic:
Spatial Computing
SubTopic:
ARKit
Tags: