Generation of tight world space bounding regions
Systems and techniques are provided for determining bounding regions for a hierarchical structure for ray tracing. For instance, a process can include obtaining an acceleration data structure, the acceleration data structure including one or more primitives of a scene object. A graph cut can be applied to the acceleration data structure. A set of nodes of the acceleration data structure can be determined based on the graph cut, wherein the determined set of nodes is located adjacent to the graph cut. A world-space bounding box can be generated for the scene object, using the set of nodes determined based on the graph cut.
1. A method of ray tracing, the method comprising:
obtaining an acceleration data structure, the acceleration data structure including one or more primitives of a scene object;
determining one or more child nodes of a root node of the acceleration data structure;
determining a Surface Area Heuristic (SAH) for each child node of the one or more child nodes;
determining a computational budget corresponding to a maximum number of nodes for a graph cut;
determining the graph cut based on the determined SAH for each child node and the computational budget;
applying the graph cut to the acceleration data structure;
determining a set of nodes of the acceleration data structure based on the graph cut, wherein the set of nodes is located adjacent to the graph cut; and
generating a world-space bounding box for the scene object, wherein the world-space bounding box is generated for the set of nodes determined based on the graph cut.
2. The method of claim 1 , further comprising:
obtaining a respective object-space bounding box for each node of the set of nodes; and
transforming each respective object-space bounding box of each node into a plurality of world-space vertices.
3. The method of claim 2 , wherein the world-space bounding box for the scene object is generated based on the plurality of world-space vertices.
4. The method of claim 1 , wherein the graph cut is applied directly above or directly below a plurality of leaf nodes of the acceleration data structure.
5. The method of claim 1 , wherein the set of nodes determined based on the graph cut includes a plurality of leaf nodes of the acceleration data structure, and wherein the plurality of leaf nodes includes each vertex of the scene object.
6. The method of claim 5 , wherein the world-space bounding box is generated based at least in part on transforming each vertex of the scene object from an object-space representation into a world-space representation.
7. The method of claim 1 , wherein the one or more primitives of the scene object are included in one or more leaf nodes of the acceleration data structure.
8. The method of claim 1 , wherein the world-space bounding box generated for the scene object is a world-space axis-aligned bounding box (AABB).
9. The method of claim 1 , wherein the acceleration data structure includes a bounding volume hierarchy (BVH).
10. The method of claim 1 , wherein the acceleration data structure includes a bottom-level acceleration structure (BLAS).
11. The method of claim 10 , wherein the BLAS:
is associated with a top-level acceleration structure (TLAS) leaf node; and
includes one or more intermediate BLAS nodes, each intermediate BLAS node including an axis-aligned bounding box (AABB) encompassing a subset of the one or more primitives of the scene object.
12. The method of claim 1 , wherein the set of nodes located adjacent to the graph cut is located above the graph cut or below the graph cut.
13. An apparatus for ray tracing, comprising:
a memory; and
one or more processors coupled to the memory, the one or more processors configured to:
obtain an acceleration data structure, the acceleration data structure including one or more primitives of a scene object;
determine one or more child nodes of a root node of the acceleration data structure;
determine a Surface Area Heuristic (SAH) for each child node of the one or more child nodes;
determine a computational budget that corresponds to a maximum number of nodes for a graph cut;
determine the graph cut based on the determined SAH for each child node and the computational budget;
apply the graph cut to the acceleration data structure;
determine a set of nodes of the acceleration data structure based on the graph cut, wherein the set of nodes is located adjacent to the graph cut; and
generate a world-space bounding box for the scene object, wherein the world-space bounding box is generated for the set of nodes determined based on the graph cut.
14. The apparatus of claim 13 , wherein the one or more processors are configured to:
obtain a respective object-space bounding box for each node of the set of nodes; and
transform each respective object-space bounding box of each node into a plurality of world-space vertices.
15. The apparatus of claim 14 , wherein the world-space bounding box for the scene object is generated based on the plurality of world-space vertices.
16. The apparatus of claim 13 , wherein the graph cut is applied directly above or directly below a plurality of leaf nodes of the acceleration data structure.
17. The apparatus of claim 13 , wherein the set of nodes determined based on the graph cut includes a plurality of leaf nodes of the acceleration data structure, and wherein the plurality of leaf nodes includes each vertex of the scene object.
18. The apparatus of claim 17 , wherein the world-space bounding box is generated based at least in part on transforming each vertex of the scene object from an object-space representation into a world-space representation.
19. The apparatus of claim 13 , wherein the one or more primitives of the scene object are included in one or more leaf nodes of the acceleration data structure.
20. The apparatus of claim 13 , wherein the world-space bounding box generated for the scene object is a world-space axis-aligned bounding box (AABB).
21. The apparatus of claim 13 , wherein the acceleration data structure includes a bounding volume hierarchy (BVH).
22. The apparatus of claim 13 , wherein the acceleration data structure includes a bottom-level acceleration structure (BLAS).
23. The apparatus of claim 22 , wherein the BLAS:
is associated with a top-level acceleration structure (TLAS) leaf node; and
includes one or more intermediate BLAS nodes, each intermediate BLAS node including an axis-aligned bounding box (AABB) encompassing a subset of the one or more primitives of the scene object.
24. The apparatus of claim 13 , wherein the set of nodes located adjacent to the graph cut is located above the graph cut or below the graph cut.
25. A non-transitory computer-readable medium having stored thereon instructions that, when executed by one or more processors, cause the one or more processors to:
obtain an acceleration data structure, the acceleration data structure including one or more primitives of a scene object;
determine one or more child nodes of a root node of the acceleration data structure;
determine a Surface Area Heuristic (SAH) for each child node of the one or more child nodes;
determine a computational budget that corresponds to a maximum number of nodes for a graph cut;
determine the graph cut based on the determined SAH for each child node and the computational budget;
apply the graph cut to the acceleration data structure;
determine a set of nodes of the acceleration data structure based on the graph cut, wherein the set of nodes is located adjacent to the graph cut; and
generate a world-space bounding box for the scene object, wherein the world-space bounding box is generated for the set of nodes determined based on the graph cut.
26. The non-transitory computer-readable medium of claim 25 , further comprising instructions that, when executed by the one or more processors, cause the one or more processors to:
obtain a respective object-space bounding box for each node of the set of nodes; and
transform each respective object-space bounding box of each node into a plurality of world-space vertices.