Accelerating triangle visibility tests for real-time ray tracing

A ray tracing acceleration hardware device, comprising:

• a memory access circuit configured to read nodes of an acceleration structure (AS) including at least one node comprising a polygon mesh primitive defining plural regions, and a visibility mask (VM) corresponding to the at least one node, wherein the VM comprises a respective visibility state for each of the plural regions of the polygon mesh;
• ray storage configured to store data representing a ray;
• and
• acceleration circuitry configured to perform operations comprising:
• detecting an intersection of the node by the ray at an intersection point;
• obtaining, from the VM, a visibility state of a region in the mesh corresponding to the intersection point;
• and
• determining, based on the visibility state, how to process the intersection.