Reality Composer objects on top of each other, such as a vase on a table cast shadow only to the ground plane and not to one another. If baked AO textures aren't an option since the vase may be moved by the user what would you suggest in order to achieve an equally good result to the default grounding shadow given that the quality of shadows is critical for an AR experience?
We don’t have any materials you can apply to objects to make them participate in the same shadows as ground planes. However, you can enable shadow casting from directional and spot lights via DirectionalLightComponent.Shadows and SpotLightComponent.Shadows. This may alter the overall lighting of your scene though.
Alternatively, we do have CustomMaterial, which allows you to create custom materials via Metal, but for this use-case may not be able to get you the desired effect.
We’re always looking to improve RealityKit, so would appreciate if you submitted a request for this via https://feedbackassistant.apple.com/