Partially resident bounding volume hierarchy
Techniques for performing ray tracing for a ray are provided. The techniques include, based on first traversal of a bounding volume hierarchy, identifying a first memory page that is classified as resident, obtaining a first portion of the bounding volume hierarchy associated with the first memory page, traversing the first portion of the bounding volume hierarchy according to a ray intersection test, based on second traversal of the bounding volume hierarchy, identifying a second memory page that is classified as valid and non-resident, and in response to the second memory page being classified as valid and non-resident, determining that a miss occurs for each node of the bounding volume hierarchy within the second memory page.
1. A method for performing ray tracing for a ray, the method comprising:
based on first traversal of a bounding volume hierarchy, identifying a first memory page that is classified as resident according to a page table;
obtaining a first portion of the bounding volume hierarchy associated with the first memory page;
traversing the first portion of the bounding volume hierarchy according to a ray intersection test;
based on second traversal of the bounding volume hierarchy, identifying a second memory page that is classified as valid and non-resident according to the page table;
in response to the second memory page being classified as valid and nonresident, processing as if a miss occurs for each node of the bounding volume hierarchy within the second memory page.
2. The method of claim 1 , wherein the first traversal of the bounding volume hierarchy comprises:
determining that the ray intersects with a first parent node that is a parent of one or more nodes of the first memory page; and
obtaining a page address for the one or more nodes from within data of the first parent node.
3. The method of claim 2 , wherein identifying the first memory page that is classified as resident comprises:
determining that the page address is indicated as being resident according to the page table.
4. The method of claim 1 , wherein the second traversal of the bounding volume hierarchy comprises:
determining that the ray intersects with a second parent node that is a parent of one or more nodes of the second memory page; and
obtaining a page address for the one or more nodes from within data of the second parent node.
5. The method of claim 4 , wherein identifying the second memory page that is classified as valid and non-resident comprises:
determining that the page address is indicated as being valid and non-resident according to the page table.
6. The method of claim 1 , further comprising:
based on third traversal of the bounding volume hierarchy, identifying a third memory page that is classified as invalid; and
generating a fault for the third memory page.
7. The method of claim 1 , further comprising:
in response to determining that the miss occurs for each node of the bounding volume hierarchy within the second memory page, executing no hit shader for any triangle node that is a descendant of any node within the second memory page.
8. The method of claim 1 , further comprising:
in response to determining that processing is to occur as if a miss occurs for each node of the bounding volume hierarchy within the second memory page, executing a miss shader for the ray.
9. The method of claim 1 , further comprising:
updating the status of memory pages of the bounding volume hierarchy based on migration of the memory pages.
10. A system for performing ray tracing for a ray, the system comprising:
a memory storing memory pages of a bounding volume hierarchy; and a processor configured to:
based on first traversal of a bounding volume hierarchy, identify a first memory page that is classified as resident according to a page table;
obtain a first portion of the bounding volume hierarchy associated with the first memory page;
traverse the first portion of the bounding volume hierarchy according to a ray intersection test;
based on second traversal of the bounding volume hierarchy, identify a second memory page that is classified as valid and non-resident according to the page table;
in response to the second memory page being classified as valid and nonresident, processing as if a miss occurs for each node of the bounding volume hierarchy within the second memory page.
11. The system of claim 10 , wherein the first traversal of the bounding volume hierarchy comprises:
determining that the ray intersects with a first parent node that is a parent of one or more nodes of the first memory page; and
obtaining a page address for the one or more nodes from within data of the first parent node.
12. The system of claim 11 , wherein identifying the first memory page that is classified as resident comprises:
determining that the page address is indicated as being resident according to the page table.
13. The system of claim 10 , wherein the second traversal of the bounding volume hierarchy comprises:
determining that the ray intersects with a second parent node that is a parent of one or more nodes of the second memory page; and
obtaining a page address for the one or more nodes from within data of the second parent node.
14. The system of claim 13 , wherein identifying the second memory page that is classified as valid and non-resident comprises:
determining that the page address is indicated as being valid and non-resident according to the page table.
15. The system of claim 10 , wherein the processor is further configured to:
based on third traversal of the bounding volume hierarchy, identify a third memory page that is classified as invalid; and
generate a fault for the third memory page.
16. The system of claim 10 , wherein the processor is further configured to:
in response to determining that the miss occurs for each node of the bounding volume hierarchy within the second memory page, execute no hit shader for any triangle node that is a descendant of any node within the second memory page.
17. The system of claim 10 , wherein the processor is further configured to:
in response to determining that processing is to occur as if a miss occurs for each node of the bounding volume hierarchy within the second memory page, execute a miss shader for the ray.
18. The system of claim 10 , wherein the processor is further configured to:
update the status of memory pages of the bounding volume hierarchy based on migration of the memory pages.
19. A non-transitory computer-readable medium storing instructions that, when executed by a processor, cause the processor to perform ray tracing for a ray, by:
based on first traversal of a bounding volume hierarchy, identifying a first memory page that is classified as resident according to a page table;
obtaining a first portion of the bounding volume hierarchy associated with the first memory page;
traversing the first portion of the bounding volume hierarchy according to a ray intersection test;
based on second traversal of the bounding volume hierarchy, identifying a second memory page that is classified as valid and non-resident according to the page table;
in response to the second memory page being classified as valid and nonresident, processing as if a miss occurs for each node of the bounding volume hierarchy within the second memory page.
20. The non-transitory computer-readable medium of claim 19 , wherein the first traversal of the bounding volume hierarchy comprises:
determining that the ray intersects with a first parent node that is a parent of one or more nodes of the first memory page; and
obtaining a page address for the one or more nodes from within data of the first parent node.