SPV_NV_shader_invocation

Name Strings

SPV_NV_shader_invocation_reorder

Contact

See Issues list in the Khronos SPIRV-Registry repository: https://github.com/KhronosGroup/SPIRV-Registry

Contributors

Ashwin Lele, NVIDIA
Eric Werness, NVIDIA
Daniel Koch, NVIDIA
Pankaj Mistry, NVIDIA

Status

Complete

Version

Last Modified Date

2023-12-06

Revision

Dependencies

This extension is written against the Unified SPIR-V Specification, Version 1.6, Revision 1.

This extension requires SPIR-V 1.4.

This extension requires SPV_KHR_ray_tracing.

This extension requires SPV_EXT_physical_storage_buffer, SPV_KHR_physical_storage_buffer or SPIR-V 1.5.

This extension interacts with SPV_NV_ray_tracing_motion_blur.

Overview

This extension adds hit objects and reordering builtins to provide finer grain control over traversal during ray tracing.

Extension Name

To use this extension within a SPIR-V module, the following OpExtension must be present in the module:

OpExtension "SPV_NV_shader_invocation_reorder"

New Capabilities

This extension introduces new capabilities:

ShaderInvocationReorderNV

New Storage Classes

Storage classes added under the ShaderInvocationReorderNV capability

HitObjectAttributeNV

New Decorations

This extension introduces new decorations:

HitObjectShaderRecordBufferNV

New Instructions

Instructions added under the ShaderInvocationReorderNV capability

OpTypeHitObjectNV
OpReorderThreadWithHintNV
OpReorderThreadWithHitObjectNV
OpHitObjectIsMissNV
OpHitObjectIsHitNV
OpHitObjectIsEmptyNV
OpHitObjectGetRayTMinNV
OpHitObjectGetRayTMaxNV
OpHitObjectGetObjectRayOriginNV
OpHitObjectGetObjectRayDirectionNV
OpHitObjectGetWorldRayOriginNV
OpHitObjectGetWorldRayDirectionNV
OpHitObjectGetObjectToWorldNV
OpHitObjectGetWorldToObjectNV
OpHitObjectGetInstanceCustomIndexNV
OpHitObjectGetInstanceIdNV
OpHitObjectGetGeometryIndexNV
OpHitObjectGetPrimitiveIndexNV
OpHitObjectGetHitKindNV
OpHitObjectGetAttributesNV
OpHitObjectGetCurrentTimeNV
OpHitObjectGetShaderBindingTableRecordIndexNV
OpHitObjectGetShaderRecordBufferHandleNV
OpHitObjectExecuteShaderNV
OpHitObjectRecordMissNV
OpHitObjectRecordMissMotionNV
OpHitObjectRecordHitWithIndexNV
OpHitObjectRecordHitWithIndexMotionNV
OpHitObjectRecordHitNV
OpHitObjectRecordHitMotionNV
OpHitObjectRecordEmptyNV
OpHitObjectTraceRayNV
OpHitObjectTraceRayMotionNV

Modifications to the SPIR-V Specification

(Modify Section 2.2.1, Instructions )

Add OpTraceRayWithHitObjectNV, OpHitObjectExecuteShaderNV to the list of shader call instructions.

(Add the following terminology to section 2.2.2, Types)

Hit object type: The type returned by OpTypeHitObjectNV.

(Add to the list of opaque types in section 2.2.2, Types)

OpTypeHitObjectNV

(Modify Section 3.2, Decorations, adding a row to the Decoration table)

Decoration	Requires
5386	ShaderInvocationReorderNV	HitObjectShaderRecordBufferNV

Decoration

Requires

5386

ShaderInvocationReorderNV

HitObjectShaderRecordBufferNV

(Modify Section 3.7, Storage Class, adding rows to the Storage Class table)

Storage Class	Enabling Capabilities	Enabled by Extension
5385	HitObjectAttributeNV Used for storing attributes of geometry intersected by a ray to be passed on to hit object instructions. Visible across all functions in the current invocation. Not shared externally. Variables declared with this storage class can be both read and written to, but cannot have initializers. Only allowed in RayGenerationKHR, ClosestHitKHR, and MissKHR execution models.	ShaderInvocationReorderNV	SPV_NV_shader_invocation_reorder

Storage Class

Enabling Capabilities

Enabled by Extension

5385

HitObjectAttributeNV
Used for storing attributes of geometry intersected by a ray to be passed on to hit object instructions. Visible across all functions in the current invocation. Not shared externally. Variables declared with this storage class can be both read and written to, but cannot have initializers. Only allowed in RayGenerationKHR, ClosestHitKHR, and MissKHR execution models.

ShaderInvocationReorderNV

SPV_NV_shader_invocation_reorder

(Modify Section 3.31, Capability, adding a row to the Capability table)

Capability	Implicitly Declares
5383	ShaderInvocationReorderNV	RayTracingKHR

Capability

Implicitly Declares

5383

ShaderInvocationReorderNV

RayTracingKHR

(Add the following line to the description of OpTypePointer, in Section 3.32.6, Type-Declaration Instructions)

If Type is OpTypeHitObjectNV, Storage Class must be Private or Function.

(Add the following line to the description of OpStore and OpLoad, in Section 3.32.8, Memory Instructions)

The Type operand to the OpTypePointer used for Pointer must not be OpTypeHitObjectNV.

(Add the following line to the description of OpCopyMemory and OpCopyMemorySized, in Section 3.32.8, Memory Instructions)

The Type operand to the OpTypePointer used for Target or Source must not be OpTypeHitObjectNV.

(Add a new sub section 3.36.Reorder Instructions)

OpReorderThreadWithHintNV

Reorder threads based on user provided hint. Similar Hint values indicate similarity of subsequent work done after this call. Behavior is implementation-defined.

Hint must be a 32-bit integer-type scalar.

Bits must be a 32-bit integer-type scalar.

This instruction is allowed only in RayGenerationKHR execution models.

Capability:
ShaderInvocationReorderNV

5280

<id> Hint

<id> Bits

OpReorderThreadWithHitObjectNV

Reorder threads based on hit object supplemented by Hint and Bits if they are optionally provided values. Behavior is implementation-defined.

Hit Object must be a pointer to hit object used to reorder threads.

Hint must be a 32-bit integer-type scalar.

Bits must be a 32-bit integer-type scalar.

Hint and Bits are optional together i.e Either both Hint and Bits should be provided or neither.

This instruction is allowed only in RayGenerationKHR execution models.

Capability:
ShaderInvocationReorderNV

2 + variable

5279

<id> Hit Object

Optional <id> Hint

Optional <id> Bits

(Add a new sub section 3.36.Hit Object Instructions)

The semantics of the arguments of OpHitObjectTraceRayNV and OpHitObjectTraceRayMotionNV are same as those with the same names of OpTraceRayKHR and OpTraceRayMotionNV as defined in the SPV_KHR_ray_tracing and SPV_NV_ray_tracing_motion_blur extensions, respectively.

OpHitObjectTraceRayNV

Traces a ray and triggers execution on any-hit or intersection shaders and populates resulting hit or miss information in the hit object.

Hit Object is a pointer to the hit object.

Acceleration Structure is the descriptor for the acceleration structure to trace into.

Ray Flags contains one or more of the ray flag values. Refer to the client API specification for details.
Cull Mask is the mask to test against the instance mask.

SBT Offset and SBT Stride control indexing into the SBT for hit shaders called from this trace. SBT stands for Shader Binding Table. Refer to the client API specification for details.

Miss Index is the index of the miss shader to be called from this trace call.

Ray Origin, Ray Tmin, Ray Direction, and Ray Tmax control the basic parameters of the ray to be traced.

Payload is a pointer to the ray payload structure to use for this trace. Payload must be the result of an OpVariable with a storage class of RayPayloadKHR or IncomingRayPayloadKHR.

Ray Flags, Cull Mask, SBT Offset, SBT Stride, and Miss Index must be a 32-bit integer type scalar.

Only the 8 least-significant bits of Cull Mask are used by this instruction - other bits are ignored.
Only the 4 least-significant bits of SBT Offset and SBT Stride are used by this instruction - other bits are ignored.
Only the 16 least-significant bits of Miss Index are used by this instruction - other bits are ignored.
Ray Origin and Ray Direction must be a 32-bit float type 3-component vector.

Ray Tmin and Ray Tmax must be a 32-bit float type scalar.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

This instruction is a shader call instruction which may invoke shaders with the IntersectionKHR and AnyHitKHR execution models.

Capability:
ShaderInvocationReorderNV

5260

<id> Hit Object

<id> Acceleration Structure

<id> Ray Flags

<id> Cull Mask

<id> SBT Offset

<id> SBT Stride

<id> Miss Index

<id> Ray Origin

<id> Ray Tmin

<id> Ray Direction

<id> Ray Tmax

<id> Payload

OpHitObjectTraceRayMotionNV

Traces a ray and triggers execution of any-hit or intersection shaders and populates resulting hit or miss information in the hit object.

Hit Object is a pointer to the hit object.

Acceleration Structure is the descriptor for the acceleration structure to trace into.

Ray Flags contains one or more of the ray flag values. Refer to the client API specification for details.
Cull Mask is the mask to test against the instance mask.

SBT Offset and SBT Stride control indexing into the SBT for hit shaders called from this trace. SBT stands for Shader Binding Table. Refer to the client API specification for details.

Miss Index is the index of the miss shader to be called from this trace call.

Ray Origin, Ray Tmin, Ray Direction, and Ray Tmax control the basic parameters of the ray to be traced.

Payload is a pointer to the ray payload structure to use for this trace. Payload must be the result of an OpVariable with a storage class of RayPayloadKHR or IncomingRayPayloadKHR.

Ray Flags, Cull Mask, SBT Offset, SBT Stride, and Miss Index must be a 32-bit integer type scalar.

Only the 8 least-significant bits of Cull Mask are used by this instruction - other bits are ignored.
Only the 4 least-significant bits of SBT Offset and SBT Stride are used by this instruction - other bits are ignored.
Only the 16 least-significant bits of Miss Index are used by this instruction - other bits are ignored.
Ray Origin and Ray Direction must be a 32-bit float type 3-component vector.

Ray Tmin and Ray Tmax must be a 32-bit float type scalar.

Current Time must be a 32-bit float type scalar.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models with SPV_NV_ray_tracing_motion_blur extension.

This instruction is a shader call instruction which may invoke shaders with the IntersectionKHR and AnyHitKHR execution models.

Capability:
ShaderInvocationReorderNV, RayTracingMotionBlurNV

5256

<id> Hit Object

<id> Acceleration Structure

<id> Ray Flags

<id> Cull Mask

<id> SBT Offset

<id> SBT Stride

<id> Miss Index

<id> Ray Origin

<id> Ray Tmin

<id> Ray Direction

<id> Ray Tmax

<id> Current Time

<id> Payload

OpHitObjectRecordHitNV

Populates the hit object to represent a hit without tracing a ray.

Hit Object is a pointer to the hit object.

Acceleration Structure is the descriptor for the acceleration structure to trace into.

Instance Id refers to the index of the instance within Acceleration Structure which to be encoded in the hit object.

Instance Id must be a 32 bit integer type scalar.
Primitive Id refers to the index of the primitive within Acceleration Strucutre which is to be encoded in the hit object.

Primitive Id must be a 32 bit integer type scalar.
Geometry Index refers to the index of the geometry within Acceleration Structure which is to be encoded in the hit object.

Geometry Index must be a 32 bit integer type scalar.
Hit Kind is the integer hit kind reported back to other shaders and accessible by the hit kind builtin.

Hit Kind must be a 32 bit unsigned integer type scalar.
SBT Record Offset and SBT Record Stride control indexing into the SBT to determine the closest-hit shader to be encoded in the hit object. SBT stands for Shader Binding Table. Refer to the client API specification for details.
SBT stands for Shader Binding Table. Refer to the client API specification for details.

SBT Record Offset and SBT Record Stride must be a 32 bit integer type scalar.
Ray Origin, Ray Tmin, Ray Direction, and Ray Tmax control the basic parameters of the ray.

Ray Origin and Ray Direction must be a 32-bit float type 3-component vector.

Ray Tmin and Ray Tmax must be a 32-bit float type scalar.

Hit Object Attributes contains the attributes of the hit which are to be encoded in Hit Object. This must be an OpVariable in HitObjectAttributeNV storage class.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5261

<id> Hit Object

<id> Acceleration Structure

<id> Instance Id

<id> Primitive Id

<id> Geometry Index

<id> Hit Kind

<id> SBT Record Offset

<id> SBT Record Stride

<id> Ray Origin

<id> Ray TMin

<id> Ray Direction

<id> Ray TMax

<id> Hit Object Attributes

OpHitObjectRecordHitMotionNV

Populates the hit object to represent a hit without tracing a ray.

Hit Object is a pointer to the hit object.

Acceleration Structure is the descriptor for the acceleration structure to trace into.

Instance Id refers to the index of the instance within Acceleration Structure which to be encoded in the hit object.

Instance Id must be a 32 bit integer type scalar.
Primitive Id refers to the index of the primitive within Acceleration Strucutre which is to be encoded in the hit object.

Primitive Id must be a 32 bit integer type scalar.
Geometry Index refers to the index of the geometry within Acceleration Structure which is to be encoded in the hit object.

Geometry Index must be a 32 bit integer type scalar.
Hit Kind is the integer hit kind reported back to other shaders and accessible by the hit kind builtin.

Hit Kind must be a 32 bit unsigned integer type scalar.
SBT Record Offset and SBT Record Stride control indexing into the SBT to determine the closest-hit shader to be encoded in the hit object. SBT stands for Shader Binding Table. Refer to the client API specification for details.
SBT stands for Shader Binding Table. Refer to the client API specification for details.

SBT Record Offset and SBT Record Stride must be a 32 bit integer type scalar.
Ray Origin, Ray Tmin, Ray Direction, and Ray Tmax control the basic parameters of the ray.

Ray Origin and Ray Direction must be a 32-bit float type 3-component vector.

Ray Tmin and Ray Tmax must be a 32-bit float type scalar.

Current Time must be a 32-bit float type scalar.

Hit Object Attributes contains the attributes of the hit which are to be encoded in Hit Object. This must be an OpVariable in HitObjectAttributeNV storage class.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models with SPV_NV_ray_tracing_motion_blur extension.

Capability:
ShaderInvocationReorderNV, RayTracingMotionBlurNV

5249

<id> Hit Object

<id> Acceleration Structure

<id> Instance Id

<id> Primitive Id

<id> Geometry Index

<id> Hit Kind

<id> SBT Record Offset

<id> SBT Record Stride

<id> Ray Origin

<id> Ray TMin

<id> Ray Direction

<id> Ray TMax

<id> Current Time

<id> Hit Object Attributes

OpHitObjectRecordHitWithIndexNV

Encodes the hit object to represent a hit without tracing a ray.

Hit Object is a pointer to the hit object.

Acceleration Structure is the descriptor for the acceleration structure to trace into.
Instance Id refers to the index of the instance within Acceleration Structure which to be encoded in the hit object.

Instance Id must be a 32 bit integer type scalar.
Primitive Id refers to the index of the primitive within Acceleration Strucutre which is to be encoded in the hit object.

Primitive Id must be a 32 bit integer type scalar.
Geometry Index refers to the index of the geometry within Acceleration Structure which is to be encoded in the hit object.

Geometry Index must be a 32 bit integer type scalar.
Hit Kind is the integer hit kind reported back to other shaders and accessible by the hit kind builtin.

Hit Kind must be a 32 bit unsigned integer type scalar.
SBT Index is record index for the closest-hit shader in the SBT to encode into the hit object.
SBT stands for Shader Binding Table. Refer to the client API specification for details.

SBT Index must be a 32 bit unsigned integer type scalar.
Ray Origin, Ray Tmin, Ray Direction, and Ray Tmax control the basic parameters of the ray.

Ray Origin and Ray Direction must be a 32-bit float type 3-component vector.

Ray Tmin and Ray Tmax must be a 32-bit float type scalar.

Hit Object Attributes contains the attributes of the hit which are to be encoded in Hit Object. This must be an OpVariable in HitObjectAttributeNV storage class.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5262

<id> Hit Object

<id> Acceleration Structure

<id> Instance Id

<id> Primitive Id

<id> Geometry Index

<id> Hit Kind

<id> SBT Index

<id> Ray Origin

<id> Ray TMin

<id> Ray Direction

<id> Ray TMax

<id> Hit Object Attributes

OpHitObjectRecordHitWithIndexMotionNV

Encodes the hit object to represent a hit without tracing a ray.

Hit Object is a pointer to the hit object.

Acceleration Structure is the descriptor for the acceleration structure to trace into.
Instance Id refers to the index of the instance within Acceleration Structure which to be encoded in the hit object.

Instance Id must be a 32 bit integer type scalar.
Primitive Id refers to the index of the primitive within Acceleration Strucutre which is to be encoded in the hit object.

Primitive Id must be a 32 bit integer type scalar.
Geometry Index refers to the index of the geometry within Acceleration Structure which is to be encoded in the hit object.

Geometry Index must be a 32 bit integer type scalar.
Hit Kind is the integer hit kind reported back to other shaders and accessible by the hit kind builtin.

Hit Kind must be a 32 bit unsigned integer type scalar.
SBT Index is record index for the closest-hit shader in the SBT to encode into the hit object.
SBT stands for Shader Binding Table. Refer to the client API specification for details.

SBT Index must be a 32 bit unsigned integer type scalar.
Ray Origin, Ray Tmin, Ray Direction, and Ray Tmax control the basic parameters of the ray.

Ray Origin and Ray Direction must be a 32-bit float type 3-component vector.

Ray Tmin and Ray Tmax must be a 32-bit float type scalar.

Current Time must be a 32-bit float type scalar.

Hit Object Attributes contains the attributes of the hit which are to be encoded in Hit Object. This must be an OpVariable in HitObjectAttributeNV storage class.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models with SPV_NV_ray_tracing_motion_blur extension.

Capability:
ShaderInvocationReorderNV, RayTracingMotionBlurNV

5250

<id> Hit Object

<id> Acceleration Structure

<id> Instance Id

<id> Primitive Id

<id> Geometry Index

<id> Hit Kind

<id> SBT Index

<id> Ray Origin

<id> Ray TMin

<id> Ray Direction

<id> Ray TMax

<id> Current Time

<id> Hit Object Attributes

OpHitObjectRecordMissNV

Encodes the hit object to represent a miss without tracing a ray.

Hit Object is a pointer to the hit object.

Miss Index is the index of the miss shader to be encode in the hit object.

Miss Index must be a 32-bit unsigned integer type scalar.
Ray Origin, Ray Tmin, Ray Direction, and Ray Tmax control the basic parameters of the ray.

Ray Origin and Ray Direction must be a 32-bit float type 3-component vector.

Ray Tmin and Ray Tmax must be a 32-bit float type scalar.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5263

<id> Hit Object

<id> Miss Index

<id> Ray Origin

<id> Ray TMin

<id> Ray Direction

<id> Ray TMax

OpHitObjectRecordMissMotionNV

Encodes the hit object to represent a miss without tracing a ray.

Hit Object is a pointer to the hit object.

Miss Index is the index of the miss shader to be encode in the hit object.

Miss Index must be a 32-bit unsigned integer type scalar.
Ray Origin, Ray Tmin, Ray Direction, and Ray Tmax control the basic parameters of the ray.

Ray Origin and Ray Direction must be a 32-bit float type 3-component vector.

Ray Tmin and Ray Tmax must be a 32-bit float type scalar.

Current Time must be a 32-bit float type scalar.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models with SPV_NV_ray_tracing_motion_blur extension.

Capability:
ShaderInvocationReorderNV, RayTracingMotionBlurNV

5251

<id> Hit Object

<id> Miss Index

<id> Ray Origin

<id> Ray TMin

<id> Ray Direction

<id> Ray TMax

<id> Current Time

OpHitObjectRecordEmptyNV

Encodes the hit object to represent an empty hit object which is neither a hit nor a miss.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5259

<id> Hit Object

OpHitObjectExecuteShaderNV

Executes the closest-hit or miss shader as encoded in the hit object.

Hit Object is a pointer to the hit object.

Payload is a pointer to the ray payload structure to use for this trace. Payload must be the result of an OpVariable with a storage class of RayPayloadKHR or IncomingRayPayloadKHR.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

This instruction is a shader call instruction which may invoke shaders with the ClosestHitKHR, and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5264

<id> Hit Object

<id> Payload

OpHitObjectGetCurrentTimeNV

Returns the current time value encoded in the hit object.

Result is the current time value as encoded in the hit object.

Result Type must be a 32-bit floating-point type scalar.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5265

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectGetAttributesNV

Returns the attributes as encoded in the hit object.

Hit Object is a pointer to the hit object.

Hit Object Attributes contains the attributes of the hit which are to be encoded in Hit Object. This must be an OpVariable in HitObjectAttributeNV storage class.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5266

<id> Hit Object

<id> Hit Object Attributes

OpHitObjectGetHitKindNV

Returns a unsigned integer value if the hit as encoded in the hit object with front face or back face of a primitive.

Result is 0xFE if hit encoded in the hit object is with front facing primitive else is 0xFF if it is back facing primitive.

Result Type must be a 32bit integer type scalar.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5267

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectGetPrimitiveIndexNV

Returns the primitive index as encoded in the hit object.

Result is the primitive index as encoded in the hit object.

Result Type must be a 32-bit integer type scalar.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5268

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectGetGeometryIndexNV

Returns the geometry index as encoded in the hit object.

Result is the geometry index as encoded in the hit object.

Result Type must be a 32-bit integer type scalar.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5269

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectGetInstanceIdNV

Returns the instance id as encoded in the hit object.

Result is the instance id as encoded in the hit object.

Result Type must be a 32-bit integer type scalar.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5270

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectGetInstanceCustomIndexNV

Returns the application specified custom index value as encoded in the hit object.

Result is the application specified custom index value as encoded in the hit object.

Result Type must be a 32-bit integer type scalar.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5271

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectGetObjectRayOriginNV

Returns the object-space ray origin as encoded in the hit object.

Result is the ray object-space ray origin as encoded in the hit object.

Result Type must be a 32-bit floating-point type 3-component vector.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5255

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectGetObjectRayDirectionNV

Returns the object-space ray direction as encoded in the hit object.

Result is the ray object-space ray direction as encoded in the hit object.

Result Type must be a 32-bit floating-point type 3-component vector.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5254

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectGetWorldRayDirectionNV

Returns the world-space ray direction as encoded in the hit object.

Result is the ray world-space ray direction as encoded in the hit object.

Result Type must be a 32-bit floating-point type 3-component vector.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5272

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectGetWorldRayOriginNV

Returns the world-space ray origin as encoded in the hit object.

Result is the ray world-space ray origin as encoded in the hit object.

Result Type must be a 32-bit floating-point type 3-component vector.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5273

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectGetObjectToWorldNV

Returns a matrix that transforms values from object-space to world-space as encoded in the hit object.

Result is the matrix.

Result Type must be a matrix with a Column Count of 4, and a Column Type that is a vector type with a Component Type that is a 32-bit floating-point type and a Component Count of 3.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5253

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectGetWorldToObjectNV

Returns a matrix that transforms values from world-space to object-space as encoded in the hit object.

Result is the matrix.

Result Type must be a matrix with a Column Count of 4, and a Column Type that is a vector type with a Component Type that is a 32-bit floating-point type and a Component Count of 3.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5253

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectGetRayTMaxNV

Returns the Ray Tmax value encoded in the hit object.
Semantics are similar to RayTMaxKHR builtin as defined in SPV_KHR_ray_tracing.
Result is the Ray Tmax value as encoded in the hit object.

Result Type must be a 32-bit floating-point type scalar.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5274

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectGetRayTMinNV

Returns the Ray Tmin value encoded in the hit object.
Semantics are similar to RayTMinKHR builtin as defined in SPV_KHR_ray_tracing.
Result is the Ray Tmin value as encoded in the hit object.

Result Type must be a 32-bit floating-point type scalar.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5275

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectGetShaderBindingTableRecordIndexNV

Returns the index for the record in shader binding table as encoded in hit object.

Result is the current time value as encoded in the hit object.

Result Type must be a 32-bit integer type scalar.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5258

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectGetShaderRecordBufferHandleNV

Returns the address of shader record buffer for the hit or miss record encoded in hit object.

Result is the address of data in shader record as encoded in the hit object.

Result Type must be a 32-bit integer type 2-component vector.

Hit Object is a pointer to the hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5257

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectIsEmptyNV

Returns a boolean indicating whether the hit object is an empty hit object.

Result is true if hit object encodes a NOP, false otherwise.

Result Type must be a boolean type scalar.

Hit Object must be a pointer to hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5276

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectIsHitNV

Returns a boolean indicating whether the hit object has encoded a hit.

Result is true if hit object encodes a hit, false otherwise.

Result Type must be a boolean type scalar.

Hit Object must be a pointer to hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5277

<id> Result Type

<id> Result

<id> Hit Object

OpHitObjectIsMissNV

Returns a boolean indicating whether the hit object has encoded a miss.

Result is true if hit object encodes a miss, false otherwise.

Result Type must be a boolean type scalar.

Hit Object must be a pointer to hit object.

This instruction is allowed only in RayGenerationKHR, ClosestHitKHR and MissKHR execution models.

Capability:
ShaderInvocationReorderNV

5278

<id> Result Type

<id> Result

<id> Hit Object

(Modify Section 3.36.6, Type-Declaration Instructions, adding a new table)

OpTypeHitObjectNV

Declares a hit object type which is an opaque object representing state during ray tracing traversal.

This type is opaque: values of this type have no defined physical size or bit pattern.

Capability:
ShaderInvocationReorderNV

5281

<id> Result

Validation Rules

An OpExtension must be added to the SPIR-V for validation layers to check legal use of this extension:

OpExtension "SPV_NV_shader_invocation_reorder"

Interactions with SPV_NV_ray_tracing_motion_blur

If the SPV_NV_ray_tracing_motion_blur extension is not supported, the OpHitObjectTraceRayMotionNV, OpHitObjectRecordHitMotionNV, OpHitObjectRecordHitWithIndexMotionNV, and OpHitObjectRecordMissMotionNV instructions are not supported.

Issues

None

Revision History

Rev	Date	Author	Changes
1	2022-09-01	Ashwin Lele	Internal revisions
2	2023-12-06	Daniel Koch	Remove references to non-existant SPIR-V definitions