Diligent::BuildTLASAttribs struct

#include <Graphics/GraphicsEngine/interface/DeviceContext.h>

Public variables

ITopLevelAS* pTLAS

Target top-level AS. Access to the TLAS must be externally synchronized.

RESOURCE_STATE_TRANSITION_MODE TLASTransitionMode

Top-level AS state transition mode (see Diligent::RESOURCE_STATE_TRANSITION_MODE).

RESOURCE_STATE_TRANSITION_MODE BLASTransitionMode

Bottom-level AS (in TLASBuildInstanceData::pBLAS) state transition mode (see Diligent::RESOURCE_STATE_TRANSITION_MODE).

TLASBuildInstanceData const * pInstances

A pointer to an array of InstanceCount TLASBuildInstanceData structures that contain instance data. If Update is true:

Uint32 InstanceCount

The number of instances. Must be less than or equal to TopLevelASDesc::MaxInstanceCount. If Update is true then count must be the same as used to build TLAS.

IBuffer* pInstanceBuffer

The buffer that will be used to store instance data during AS building. The buffer size must be at least TLAS_INSTANCE_DATA_SIZE * InstanceCount. The buffer must be created with BIND_RAY_TRACING flag.

Uint32 InstanceBufferOffset

Offset from the beginning of the buffer to the location of instance data.

RESOURCE_STATE_TRANSITION_MODE InstanceBufferTransitionMode

Instance buffer state transition mode (see Diligent::RESOURCE_STATE_TRANSITION_MODE).

Uint32 HitGroupStride

The number of hit shaders that can be bound for a single geometry or an instance (depends on BindingMode).

Uint32 BaseContributionToHitGroupIndex

Base offset for the hit group location. Can be used to bind hit shaders for multiple acceleration structures, see IShaderBindingTable::BindHitGroupForGeometry().

HIT_GROUP_BINDING_MODE BindingMode

Hit shader binding mode, see Diligent::SHADER_BINDING_MODE. Used to calculate TLASBuildInstanceData::ContributionToHitGroupIndex.

IBuffer* pScratchBuffer

Buffer that is used for acceleration structure building. Must be created with BIND_RAY_TRACING. Call ITopLevelAS::GetScratchBufferSizes().Build to get the minimal size for the scratch buffer. Access to the TLAS must be externally synchronized.

Uint32 ScratchBufferOffset

Offset from the beginning of the buffer.

RESOURCE_STATE_TRANSITION_MODE ScratchBufferTransitionMode

Scratch buffer state transition mode (see Diligent::RESOURCE_STATE_TRANSITION_MODE).

Bool Update

if false then TLAS will be built from scratch. If true then previous content of TLAS will be updated. pTLAS must be created with RAYTRACING_BUILD_AS_ALLOW_UPDATE flag. An update will be faster than building an acceleration structure from scratch.

Variable documentation