VkClusterAccelerationStructureGeometryIndexAndGeometryFlagsNV(3)

Name

VkClusterAccelerationStructureGeometryIndexAndGeometryFlagsNV - Parameters describing geometry index and flags values for cluster acceleration structure

C Specification

The VkClusterAccelerationStructureGeometryIndexAndGeometryFlagsNV structure is defined as:

// Provided by VK_NV_cluster_acceleration_structure
typedef struct VkClusterAccelerationStructureGeometryIndexAndGeometryFlagsNV {
    uint32_t    geometryIndex:24;
    uint32_t    reserved:5;
    uint32_t    geometryFlags:3;
} VkClusterAccelerationStructureGeometryIndexAndGeometryFlagsNV;

Members

geometryIndex specifies the geometry index for all triangles in the cluster acceleration structure.
reserved is reserved for future use.
geometryFlags is a bitmask of VkClusterAccelerationStructureGeometryFlagBitsNV values describing geometry flags for the cluster acceleration structure.

Description

The C language specification does not define the ordering of bit-fields, but in practice, this structure produces the correct layout with existing compilers. The intended bit pattern is the following:

geometryIndex, reserved and mask occupy the same memory as if a single uint32_t was specified in their place
- geometryIndex occupies the 24 least significant bits of that memory
- geometryFlags occupies the 3 most significant bits of that memory

If a compiler produces code that diverges from that pattern, applications must employ another method to set values according to the correct bit pattern.

Valid Usage

VUID-VkClusterAccelerationStructureGeometryIndexAndGeometryFlagsNV-reserved-10487
reserved must be 0

Document Notes

For more information, see the Vulkan Specification.

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.