US 11,928,770 B2
BVH node ordering for efficient ray tracing
John Alexandre Tsakok, Santa Clara, CA (US); and Skyler Jonathon Saleh, San Diego, CA (US)
Assigned to Advanced Micro Devices, Inc., Santa Clara, CA (US)
Filed by Advanced Micro Devices, Inc., Santa Clara, CA (US)
Filed on Dec. 27, 2021, as Appl. No. 17/562,271.
Prior Publication US 2023/0206539 A1, Jun. 29, 2023
Int. Cl. G06T 15/06 (2011.01); G06T 15/00 (2011.01)
CPC G06T 15/06 (2013.01) [G06T 15/005 (2013.01); G06T 2210/21 (2013.01)] 24 Claims
OG exemplary drawing
 
1. A method for traversing nodes in a bounding volume hierarchy (BVH) tree by an intersection engine, comprising:
receiving a traversal instruction including a tracing-mode, ray data for a ray, and an identifier of a node to be traversed, wherein the tracing-mode comprises a closest hit mode and a first hit mode and the ray data includes a ray origin;
in response to a condition where the node to be traversed is an internal node, determining, according to the tracing-mode, an order in which children nodes of the node are to be next traversed based on a respective distance to each respective children node among the children nodes; and
outputting identifiers of the children nodes in the determined order for the traversal instruction,
wherein the respective distance is calculated by averaging a first distance between the ray origin and a first location at which the ray enters a volume associated with a respective children node and a second distance between the ray origin and a second location at which the ray exits the volume for the traversal instruction.