depthPrepassParticipates property
Whether this material's geometry joins the camera depth prepass that feeds the screen-space chain (ambient occlusion, contact shadows, reflections, depth of field).
Opaque materials do; translucent ones normally do not (the chain wants the opaque scene). A translucent surface that must be known to the screen-space chain, the shadow catcher, overrides this to true so occlusion is evaluated at its own depth instead of the backdrop's.
Implementation
@override
bool get depthPrepassParticipates => true;