Name Strings
SPV_NV_cluster_acceleration_structure
Contact
See Issues list in the Khronos SPIRV-Registry repository: https://github.com/KhronosGroup/SPIRV-Registry
Contributors
-
Pyarelal Knowles, NVIDIA
-
Ashwin Lele, NVIDIA
-
Eric Werness, NVIDIA
-
Vikram Kushwaha, NVIDIA
Status
-
Complete
Version
Last Modified Date |
2025-01-01 |
Revision |
1 |
Dependencies
This extension is written against the SPIR-V Specification, Version 1.6 Revision 1.
This extension requires SPIR-V 1.4.
This extension interacts with SPV_KHR_ray_tracing and SPV_KHR_ray_query.
Overview
This extension adds new functionality to support the Vulkan VK_NV_cluster_acceleration_structure extension in SPIR-V.
Extension Name
To use this extension within a SPIR-V module, the following OpExtension must be present in the module:
OpExtension "SPV_NV_cluster_acceleration_structure"
New Capabilities
This extension introduces new capabilities:
RayTracingClusterAccelerationStructureNV
New Builtins
Builtins added under the RayTracingClusterAccelerationStructureNV capability
ClusterIDNV
New Instructions
Instructions added under the RayTracingClusterAccelerationStructureNV capability
OpRayQueryGetIntersectionClusterIdNV OpHitObjectGetClusterIdNV
Modifications to the SPIR-V Specification, Version 1.1
- (Modify Section 3.21, Builtin, adding rows to the Builtin table)
-
Decoration Enabling Capabilities 5436
ClusterIDNV
Provides triangle cluster ID of a hit with a triangle for the ray being traced, or -1 if the hit object is not a cluster object.
Allowed in AnyHitKHR and ClosestHitKHR ray tracing execution models.RayTracingClusterAccelerationStructureNV
- (Modify Section 3.31, Capability, adding a row to the Capability table)
-
Capability Implicitly Declares 5437
RayTracingClusterAccelerationStructureNV
RayTracingKHR
- (Add a new sub section 3.36.RQInstructions, Ray Query Instructions)
-
OpRayQueryGetIntersectionClusterIdNV
Returns the triangle cluster ID corresponding to the current intersection of the ray if the intersection is with a cluster object. Returns -1 otherwise.
Result is the returned cluster ID.
Result Type must be a 32-bit integer type scalar.
Intersection must be the <id> of a constant instruction with a 32-bit scalar integer type.
Intersection identifies which intersection values should be returned for, either the current candidate or the closest recorded hit so far; see Ray Query Intersection.
Ray Query is a pointer to the ray query object.
If Intersection is RayQueryCandidateIntersectionKHR, behavior is undefined if OpRayQueryProceedKHR was not executed on the same ray query object, or if the last value returned by such an execution of OpRayQueryProceedKHR was not true.
If Intersection is RayQueryCommittedIntersectionKHR, behavior is undefined if there is no current committed intersection (see OpRayQueryCommittedTypeKHR).Capability:
RayTracingClusterAccelerationStructureNV5
5345
<id> Result Type
<id> Result
<id> Ray Query
<id> Intersection
- (Modify sub section 3.36.Hit Object Instructions, adding)
-
Validation Rules
An OpExtension must be added to the SPIR-V for validation layers to check legal use of this extension:
OpExtension "SPV_NV_cluster_acceleration_structure"
Interactions with SPV_KHR_ray_tracing
Builtin ClusterIDNV is supported only if SPV_KHR_ray_tracing is supported.
Interactions with SPV_KHR_ray_query
OpRayQueryGetIntersectionClusterIdNV is supported only if SPV_KHR_ray_query is supported.
Interactions with SPV_NV_shader_invocation_reorder
OpHitObjectGetClusterIdNV is supported only if SPV_NV_shader_invocation_reorder is supported.
Issues
None
Revision History
| Rev | Date | Author | Changes |
|---|---|---|---|
1 |
2025-01-01 |
Pyarelal Knowles |
Internal revisions |