VkPartitionedAccelerationStructureUpdateInstanceDataNV

The VkPartitionedAccelerationStructureUpdateInstanceDataNV structure is defined as:

typedef struct VkPartitionedAccelerationStructureUpdateInstanceDataNV {
    uint32_t instanceIndex;
    uint32_t instanceContributionToHitGroupIndex;
    VkDeviceAddress accelerationStructure;
} VkPartitionedAccelerationStructureUpdateInstanceDataNV;

• instanceIndex is the index of the instance being updated.
• instanceContributionToHitGroupIndex is a 24-bit per instance value added in the indexing into the shader binding table to fetch the hit group to use.
• accelerationStructure is the device address of the bottom level acceleration structure or a clustered bottom level acceleration structure whose instance is being updated. The instance is disabled if the device address is 0.

If the instance was originally disabled by specifying a 0 in VkPartitionedAccelerationStructureWriteInstanceDataNV::accelerationStructure, it can not be updated to a new acceleration structure as the instance may have been permanently disabled by the implementation.

To avoid a refit, the new acceleration structure must be within the bounding box specified by VkPartitionedAccelerationStructureWriteInstanceDataNV::explicitAABB when the instance was first created.