Name Strings

SPV_KHR_ray_tracing

Contact

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

Contributors

  • Eric Werness, NVIDIA

  • Ashwin Lele, NVIDIA

  • Daniel Koch, NVIDIA

  • Tobias Hector, AMD

  • Nicolai Haehnle, AMD

  • David Neto, Google

  • Alan Baker, Google

  • John Kessenich, Google

  • Joshua Barczak, Intel

  • Faith Ekstrand, Intel

  • Hans-Kristian Arntzen, Valve

Status

  • Complete

  • Ratified by the Khronos Board 2020-11-20

Version

Last Modified Date

2022-08-17

Revision

24

Dependencies

This extension is written against the SPIR-V Specification, Version 1.5 Revision 1.

This extension requires SPIR-V 1.4.

This extension interacts with SPV_KHR_ray_query.

Overview

This extension adds new functionality to support the Vulkan VK_KHR_ray_tracing_pipeline 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_KHR_ray_tracing"

New Execution Models

This extension introduces new execution models:

RayGenerationKHR
IntersectionKHR
AnyHitKHR
ClosestHitKHR
MissKHR
CallableKHR

these depend on the RayTracingKHR capability.

New Capabilities

This extension introduces new capabilities:

RayTracingKHR
RayTraversalPrimitiveCullingKHR

New Storage Classes

Storage classes added under the RayTracingKHR capability

RayPayloadKHR
IncomingRayPayloadKHR
HitAttributeKHR
CallableDataKHR
IncomingCallableDataKHR
ShaderRecordBufferKHR

New Builtins

Builtins added under the RayTracingKHR capability

LaunchIdKHR
LaunchSizeKHR
InstanceCustomIndexKHR
RayGeometryIndexKHR
WorldRayOriginKHR
WorldRayDirectionKHR
ObjectRayOriginKHR
ObjectRayDirectionKHR
RayTminKHR
RayTmaxKHR
ObjectToWorldKHR
WorldToObjectKHR
HitKindKHR
IncomingRayFlagsKHR

New Instructions

Instructions added under the RayTracingKHR capability

OpReportIntersectionKHR
OpIgnoreIntersectionKHR
OpTerminateRayKHR
OpTraceRayKHR
OpTypeAccelerationStructureKHR
OpExecuteCallableKHR
OpConvertUToAccelerationStructureKHR

Modifications to the SPIR-V Specification

(Modify Section 2.2.1, Instructions )

Shader Call Instruction: An instruction which may cause execution to continue elsewhere by creating one or more invocations that execute other shaders. The OpTraceRayKHR, OpExecuteCallableKHR, and OpReportIntersectionKHR instructions are shader call instructions.

(Modify Section 2.2.2, Types )

add OpTypeAccelerationStructureKHR to list of opaque types

(Modify Section 2.2.5, Control Flow)

Add OpIgnoreIntersectionKHR and OpTerminateRayKHR to the list of Termination Instructions.

(Modify Section 2.16.1, Universal Validation Rules)

Modify the list following the statement:

A pointer operand to an OpFunctionCall must point into one of the following storage classes:

to include ShaderRecordBufferKHR.

Change the second bullet under "Any pointer operand to an OpFunctionCall must be" to include OpTypeAccelerationStructureKHR:

  • a pointer to an element in an array that is a memory object declaration, where the element type is OpTypeSampler, OpTypeImage, or OpTypeAccelerationStructureKHR.

Add a new bullet under "Data rules":

  • Instructions accessing a scalar acceleration structure out of a composite must only use dynamically-uniform indexes, unless the index is decorated with NonUniformEXT. They must be in the same block in which their Result <id> are consumed. Such Result <id> must not appear as operands to OpPhi or OpSelect instructions, or any instructions other than the ray tracing instructions specified to operate on them.

Modify the item under "Memory model":

Memory accesses that use NonPrivatePointer must use pointers in the Uniform, Workgroup, CrossWorkgroup, Generic, Image, or StorageBuffer storage classes.

to include ShaderRecordBufferKHR.

(Modify Section 2.16.2, Universal Rules for Shader Capabilities)

Modify the item:

  • Composite objects in the StorageBuffer, PhysicalStorageBuffer, Uniform, and PushConstant Storage Classes must be explicitly laid out. …​

to include ShaderRecordBufferKHR.

(Modify Section 3.3, Execution Model, adding rows to the Execution Model table)
Execution Model Enabling Capabilities

5313

RayGenerationKHR
Ray generation shading stage.

RayTracingKHR

5314

IntersectionKHR
Intersection shading stage.

RayTracingKHR

5315

AnyHitKHR
Any hit shading stage.

RayTracingKHR

5316

ClosestHitKHR
Closest hit shading stage.

RayTracingKHR

5317

MissKHR
Miss shading stage.

RayTracingKHR

5318

CallableKHR
Ray callable shading stage.

RayTracingKHR
(Modify Section 3.7, Storage Class, adding rows to the Storage Class table)
Storage Class Enabling Capabilities Enabled by Extension

5328

CallableDataKHR
Used for storing arbitrary data associated with a ray to pass to callables. 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, CallableKHR, and MissKHR execution models.

RayTracingKHR

SPV_KHR_ray_tracing

5329

IncomingCallableDataKHR
Used for storing arbitrary data from parent sent to current callable stage invoked from OpExecuteCallable. Visible across all functions in current invocation. Not shared externally. Variables declared with the storage class are allowed only in CallableKHR execution models. Can be both read and written to in above execution models, but cannot have initializers.

RayTracingKHR

SPV_KHR_ray_tracing

5338

RayPayloadKHR
Used for storing payload data associated with a ray. 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.

RayTracingKHR

SPV_KHR_ray_tracing

5339

HitAttributeKHR
Used for storing attributes of geometry intersected by a ray. Visible across all functions in the current invocation. Not shared externally. Variables declared with this storage class are allowed only in IntersectionKHR, AnyHitKHR and ClosestHitKHR execution models. They can be written to only in IntersectionKHR execution model and read from only in AnyHitKHR and ClosestHitKHR execution models. They cannot have initializers.

RayTracingKHR

SPV_KHR_ray_tracing

5342

IncomingRayPayloadKHR
Used for storing parent payload data associated with a ray in current stage invoked from a trace call. Visible across all functions in current invocation. Not shared externally. Variables declared with the storage class are allowed only in AnyHitKHR, ClosestHitKHR and MissKHR execution models. Can be both read and written to in above execution models, but cannot have initializers.

RayTracingKHR

SPV_KHR_ray_tracing

5343

ShaderRecordBufferKHR
Used for storing data in shader record associated with each unique shader in ray_tracing pipeline. Visible across all functions in current invocation. Can be initialized externally via API. Variables declared with this storage class are allowed in RayGenerationKHR, IntersectionKHR, AnyHitKHR, ClosestHitKHR, MissKHR and CallableKHR execution models, are read-only, and cannot have initializers. Refer to the client API for details on shader records.

RayTracingKHR

SPV_KHR_ray_tracing
(Modify Section 3.21, Builtin, adding rows to the Builtin table)
Decoration Enabling Capabilities

5319

LaunchIdKHR
Index of work item being processed in current invocation of ray tracing shader stage. Allowed in all ray tracing execution models.

Refer to the client API specification for more details.

RayTracingKHR

5320

LaunchSizeKHR
Width and height dimensions passed to vkCmdTraceRaysKHR call which resulted in invocation of current ray tracing shader stage. Allowed in all ray tracing execution models.

Refer to the client API specification for more details.

RayTracingKHR

5321

WorldRayOriginKHR
World-space origin coordinates for the ray being traced in the IntersectionKHR, AnyHitKHR, ClosestHitKHR, or MissKHR execution models.

Refer to the client API specification for more details.

RayTracingKHR

5322

WorldRayDirectionKHR
World-space direction for the ray being traced in the IntersectionKHR, AnyHitKHR, ClosestHitKHR, or MissKHR execution models.

Refer to the client API specification for more details.

RayTracingKHR

5323

ObjectRayOriginKHR
Object-space origin coordinates for the ray being traced in the IntersectionKHR, AnyHitKHR, or ClosestHitKHR execution models.

Refer to the client API specification for more details.

RayTracingKHR

5324

ObjectRayDirectionKHR
Object-space direction for the ray being traced in the IntersectionKHR, AnyHitKHR, or ClosestHitKHR execution models.

Refer to the client API specification for more details.

RayTracingKHR

5325

RayTminKHR
The current Tmin parametric value for the ray being traced in the IntersectionKHR, AnyHitKHR, ClosestHitKHR, or MissKHR execution models.

Refer to the client API specification for more details.

RayTracingKHR

5326

RayTmaxKHR
The current Tmax parametric value for the ray being traced in the IntersectionKHR, AnyHitKHR, ClosestHitKHR, or MissKHR execution models.

Refer to the client API specification for more details.

RayTracingKHR

5327

InstanceCustomIndexKHR
Application specified value associated with the instance that was hit by the current ray in the IntersectionKHR, AnyHitKHR, ClosestHitKHR execution models.

Refer to the client API specification for more details.

RayTracingKHR

5330

ObjectToWorldKHR
The 4x3 object to world transformation matrix for the ray being traced in the IntersectionKHR, AnyHitKHR, or ClosestHitKHR execution models.

Refer to the client API specification for more details.

RayTracingKHR

5331

WorldToObjectKHR
The 4x3 world to object transformation matrix for the ray being traced in the IntersectionKHR, AnyHitKHR, or ClosestHitKHR execution models.

Refer to the client API specification for more details.

RayTracingKHR

5333

HitKindKHR
The hit kind of the hit for the ray being traced in the AnyHitKHR or ClosestHitKHR execution models.

Refer to the client API specification for more details.

RayTracingKHR

5351

IncomingRayFlagsKHR
The ray flags in current stage as passed in through trace call in parent. Available in AnyHitKHR, ClosestHitKHR, IntersectionKHR, and MissKHR stage

Refer to the client API specification for more details.

RayTracingKHR

5352

RayGeometryIndexKHR
Implementation defined index corresponding to the geometry that was hit by the current ray in the IntersectionKHR, AnyHitKHR, or ClosestHitKHR execution models.

Refer to the client API specification for more details.

RayTracingKHR
(Modify the definition of following BuiltIns, allowing them to be used in IntersectionKHR, AnyHitKHR, or ClosestHitKHR Execution Models.)
BuiltIn Enabling Capabilities Enabled by Extension

6

InstanceId
Input Instance identifier. See the client API specifications for more detail.

Instance ID in a Vertex Execution Model

Shader

Instance ID in an IntersectionKHR, AnyHitKHR, or ClosestHitKHR Execution Model

RayTracingKHR

SPV_KHR_ray_tracing

7

PrimitiveId
Primitive identifier. See the client API specifications for more detail.

Primitive ID in a Geometry Execution Model

Geometry

Primitive ID in a Tessellation Execution Model

Tessellation

Primitive ID in an IntersectionKHR, AnyHitKHR, or ClosestHitKHR Execution Model

RayTracingKHR

SPV_KHR_ray_tracing
(Modify Section 3.25, Memory Semantics <id>)

Modify the UniformMemory cell:

Apply the memory-ordering constraints to StorageBuffer, PhysicalStorageBuffer, or Uniform Storage Class memory.

to include ShaderRecordBufferKHR.

(Modify Section 3.27, Scope <id>, adding a new row to the Scope table)
Scope Enabling Capabilities

6

ShaderCallKHR
Scope is the set of invocations that are shader-call-related in a ray tracing Execution Model. Set the client API specification for details.

RayTracingKHR
(Add a new sub-section 3.RF, Ray Flags, adding a new table)

3.RF, Ray Flags

Flags controlling the properties of an OpTraceRayKHR instruction or for comparing against the IncomingRayFlagsKHR builtin. See the client API specification for more details.

Despite being a mask and allowing multiple bits to be combined, the following combinations are invalid:

  • if more than one of these four bits are set: OpaqueKHR, NoOpaqueKHR, CullOpaqueKHR, CullNoOpaqueKHR.

  • if more than one of these three bits are set: SkipTrianglesKHR, CullBackFacingTrianglesKHR, CullFrontFacingTrianglesKHR.

  • if more than one of these two bits are set: SkipTrianglesKHR, SkipAABBsKHR.

Ray Flags Enabling Capabilities

0

NoneKHR
No flags specified.

RayTracingKHR

1

OpaqueKHR
Force all intersections with the trace to be opaque.
See the Ray Opacity Culling section in the Vulkan API specification.

RayTracingKHR

2

NoOpaqueKHR
Force all intersections with the trace to be non-opaque.
See the Ray Opacity Culling section in the Vulkan API specification.

RayTracingKHR

4

TerminateOnFirstHitKHR
Accept the first hit discovered.
See the Ray Closest Hit Determination section in the Vulkan API specification.

RayTracingKHR

8

SkipClosestHitShaderKHR
Do not execute a closest hit shader.
See the Ray Result Determination section in the Vulkan API specification.

RayTracingKHR

16

CullBackFacingTrianglesKHR
Do not intersect with the back face of triangles.
See the Ray Face Culling section in the Vulkan API specification.

RayTracingKHR

32

CullFrontFacingTrianglesKHR
Do not intersect with the front face of triangles.
See the Ray Face Culling section in the Vulkan API specification.

RayTracingKHR

64

CullOpaqueKHR
Do not intersect with opaque geometry.
See the Ray Opacity Culling section in the Vulkan API specification.

RayTracingKHR

128

CullNoOpaqueKHR
Do not intersect with non-opaque geometry.
See the Ray Opacity Culling section in the Vulkan API specification.

RayTracingKHR

256

SkipTrianglesKHR
Do not intersect with any triangle geometries. See the Ray Primitive Culling section in the Vulkan API specification.

RayTraversalPrimitiveCullingKHR

512

SkipAABBsKHR
Do not intersect with any aabb geometries. See the Ray Primitive Culling section in the Vulkan API specification.

RayTraversalPrimitiveCullingKHR
(Add a new sub-section 3.HK, Hit Kinds, adding a new table)

3.HK, Hit Kinds

Values returned in the variable decorated as HitKindKHR from built-in intersections with triangle geometry. See the Ray Face Culling section in the Vulkan API specification.

Hit Kind Enabling Capabilities

0xFE

HitKindFrontFacingTriangleKHR
The intersection was with front-facing geometry.

RayTracingKHR

0xFF

HitKindBackFacingTriangleKHR
The intersection was with back-facing geometry.

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

4479

RayTracingKHR
Uses the RayGenerationKHR, IntersectionKHR, AnyHitKHR, ClosestHitKHR, MissKHR, or CallableKHR Execution Models

Shader

4478

RayTraversalPrimitiveCullingKHR
Uses SkipAABBsKHR or SkipTrianglesKHR

RayTracingKHR

Modify the StorageBuffer16BitAccess cell to include ShaderRecordBufferKHR.

Modify the UniformAndStorageBuffer16BitAccess cell to include ShaderRecordBufferKHR.

Modify the StorageBuffer8BitAccess cell to include ShaderRecordBufferKHR.

Modify the UniformAndStorageBuffer8BitAccess cell to include ShaderRecordBufferKHR.

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

OpTypeAccelerationStructureKHR

Declares an acceleration structure type which is an opaque reference to acceleration structure handle as defined in the client API specification.

Consumed by OpRayQueryInitializeKHR and OpTraceRayKHR

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

Capability:
RayTracingKHR

2

5341

<id> Result
(Modify Section 3.36.8, Memory Instructions)

Modify the following sentence in the description of OpPtrAccessChain

For objects in the Uniform, StorageBuffer, or PushConstant storage classes, the element’s address or location is calculated using a stride, which will be the Base-type’s Array Stride when the Base type is decorated with ArrayStride.

to include ShaderRecordBufferKHR.

(Modify Section 3.36.11, Conversion Instructions, adding a new table)

OpConvertUToAccelerationStructureKHR

Converts a 64-bit integer into an OpTypeAccelerationStructureKHR.

Acceleration Structure must either be a 64-bit scalar of integer type, whose Signedness operand is 0, or a 2-component vector of 32-bit integer type, whose Signedness operand is 0.
A vector value input behaves as-if OpBitcast converts the value to a 64-bit scalar integer first.
Acceleration Structure represents the address of a valid acceleration structure.
Refer to the client API specification for details.

Result Type must be an OpTypeAccelerationStructureKHR.

Capability:
RayTracingKHR

4

4447

<id> Result Type

<id> Result

<id> Acceleration Structure
(Add a new sub section 3.36.RT, Ray Tracing Instructions, adding to end of list of instructions)

OpTraceRayKHR

Trace a ray into the acceleration structure.

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

Ray Flags contains one or more of the Ray Flag values.

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, AnyHitKHR, ClosestHitKHR, and MissKHR execution models.

Capability:
RayTracingKHR

12

4445

<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

OpReportIntersectionKHR

Reports an intersection back to the traversal infrastructure.

If the intersection occurred within the current ray interval, the intersection confirmation is performed (see the API specification for more details). If the value of Hit falls outside the current ray interval, the hit is rejected.

Returns True if the hit was accepted by the ray interval and the intersection was confirmed. Returns False otherwise.

Hit is the floating point parametric value along ray for the intersection.

Hit Kind is the integer hit kind reported back to other shaders and accessible by the hit kind builtin.

Result Type must be a scalar boolean.

Hit must be a 32-bit float type scalar.

Hit Kind must be a 32-bit unsigned integer type scalar.

This instruction is allowed only in IntersectionKHR execution model.

This instruction is a shader call instruction which may invoke shaders with the AnyHitKHR execution model.

Capability:
RayTracingKHR

5

5334

<id> Result Type

<id> Result

<id> Hit

<id> Hit Kind

OpIgnoreIntersectionKHR

Ignores the current potential intersection, terminating the invocation that executes it, and continues the ray traversal.

This instruction must be the last instruction in a block.

This instruction is allowed only in AnyHitKHR execution model.

Capability:
RayTracingKHR

1

4448

OpTerminateRayKHR

Terminates the invocation that executes it, stops the ray traversal, accepts the current hit, and invokes the ClosestHitKHR execution model (if active).

This instruction must be the last instruction in a block.

This instruction is allowed only in AnyHitKHR execution model.

Capability:
RayTracingKHR

1

4449

OpExecuteCallableKHR

Invoke a callable shader

SBT Index is the index into the SBT table to select callable shader to execute

Callable Data is a pointer to the callable data to pass into the called shader. Callable Data must be the result of an OpVariable with a storage class of CallableDataKHR or IncomingCallableDataKHR.

SBT Index must be a 32-bit unsigned integer type scalar.

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

This instruction is a shader call instruction which will invoke a shader with the CallableKHR execution model.

Capability:
RayTracingKHR

3

4446

<id> SBT Index

<id> Callable Data

Validation Rules

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

OpExtension "SPV_KHR_ray_tracing"

Interactions with SPV_KHR_ray_query

OpTypeAccelerationStructureKHR, RayTraversalPrimitiveCullingKHR, OpConvertUToAccelerationStructureKHR and the Ray Flags are added by both this extension and SPV_KHR_ray_query; they are intended to have identical definitions, and can be enabled by either extension’s capability, for use with the instructions under that same capability. If SPV_KHR_ray_query is not supported, ignore any references to OpRayQueryInitializeKHR.

Issues

1) Should the global variables be listed in the entrypoint interface?

Discussion: This makes the consumer lives easier in the presence of multiple entry points. This is already required in SPIR-V 1.4, but if using an earlier version of SPIR-V it is actually illegal.

Resolved: Require SPIR-V 1.4 to make it simpler for consumers. SPV_NV_ray_tracing needs to work both ways since it pre-dates SPIR-V 1.4, but implementations which only support SPV_KHR_ray_tracing will benefit from this requirement.

2) What are the differences between provisional and final?

Discussion:

  • change RayTracingProvisionalKHR to RayTracingKHR and assign new token (4479)

  • change ray payloads and callable data to pointers rather than integer locations (this resulted in new opcodes for OpTraceRayKHR (4445) and OpExecuteCallableKHR (4446))

  • added OpConvertUToAccelerationStructureKHR (4447) instruction to convert from a 64-bit acceleration structure pointer to an OpTypeAccelerationStructureKHR to enable tracing by handle

  • Assign new opcodes for OpIgnoreIntersectionKHR (4448) and OpTerminateRayKHR (4449) and specify that they are termination instructions.

3) Are OpReportIntersectionKHR and OpIgnoreIntersectionKHR terminators like OpTerminateInvocation or just OpKill?

Resolved: They are meant to unambiguously end execution similarly to OpTerminateInvocation. We are trying to avoid the mess caused by OpKill.

Revision History

Rev Date Author Changes

1

2019-04-30

Daniel Koch

Fork from SPV_NV_ray_tracing rev 4.

2

2019-04-30

Daniel Koch

Add Ray Flags documentation.

3

2019-06-20

Tobias Hector

Add RayGeometryIndexKHR.

4

2019-10-25

Tobias Hector

Add description to ray flags.

5

2019-11-20

Daniel Koch

OpTraceKHR → OpTraceRayKHR. Add references to API spec for ray flags. Add Hit Kind documentation.

6

2019-11-25

Daniel Koch

Add ShaderCallKHR scope. Document payload for OpTraceRayKHR.

7

2019-11-27

Daniel Koch

Disallow initializers on all new storage classes.

8

2019-12-03

Tobias Hector

Add interactions with SPV_KHR_ray_query.

9

2019-12-05

Tobias Hector

Add RayTraversalPrimitiveCullingKHR capability and the SkipAABBsKHR/SkipTrianglesKHR ray flags.

10

2019-12-05

Daniel Koch

Base on SPIR-V 1.5

11

2019-12-11

Daniel Koch

add Provisional string to capabilities, and reassign token for RayTracingProvisionalKHR.

12

2020-02-20

Eric Werness

Miss does not have object parameters.

13

2020-02-22

Tobias Hector

Removed HitTKHR alias of RayTmaxKHR

14

2020-04-22

Daniel Koch

Require SPIR-V 1.4.

15

2020-06-03

Daniel Koch

Update capabilities tables to match SPIR-V 1.5.

16

2020-06-04

Faith Ekstrand

Make ray payloads and callable data pointers rather than integer locations

17

2020-06-05

Hans-Kristian Arntzen

Add conversion from 64-bit acceleration structure pointer to OpTypeAccelerationStructureKHR

18

2020-07-03

Daniel Koch

Remove provisional notices and update capabilities

19

2020-07-10

Tobias Hector

Clarify that subset of bits are used for trace operation

20

2020-09-25

Daniel Koch

Require explicit layouts for ShaderRecordBufferKHR and otherwise just generally treat it as the StorageBuffer storage class. Clarify OpReportIntersection behavior if out of range Hit (vulkan#2359).

21

2020-10-01

Daniel Koch

Update OpIgnoreIntersectionKHR and OpTerminateRayKHR behavior (they are terminators) and assign new opcodes (vulkan#2374).

22

2021-05-13

Eric Werness

Fix ray payload allowed execution models to exclude any hit.

23

2022-05-27

Daniel Koch

disallow more combinations of ray flags (vk-gl-cts#3647)

24

2022-08-17

Daniel Koch

OpExecuteCallableKHR SBT Index must be 32-bit unsigned integer (#156)