Name

VK_HUAWEI_invocation_mask - device extension

VK_HUAWEI_invocation_mask

Name String

VK_HUAWEI_invocation_mask

Extension Type

Device extension

Registered Extension Number

371

Revision

1

Ratification Status

Not ratified

Extension and Version Dependencies

VK_KHR_ray_tracing_pipeline and VK_KHR_synchronization2

Contact

• Pan Gao @PanGao-h%0A*Here describe the issue or question you have about the VK_HUAWEI_invocation_mask extension*

Extension Proposal

VK_HUAWEI_invocation_mask

Other Extension Metadata

Last Modified Date

2021-05-27

Interactions and External Dependencies

• This extension requires VK_KHR_ray_tracing_pipeline, which allow to bind an invocation mask image before the ray tracing command
• This extension requires VK_KHR_synchronization2, which allows new pipeline stage for the invocation mask image

Contributors

• Yunpeng Zhu
• Juntao Li, Huawei
• Liang Chen, Huawei
• Shaozhuang Shi, Huawei
• Hailong Chu, Huawei

Description

The rays to trace may be sparse in some use cases. For example, the scene only have a few regions to reflect. Providing an invocation mask image to the ray tracing commands could potentially give the hardware the hint to do certain optimization without invoking an additional pass to compact the ray buffer.

New Commands

• cmdBindInvocationMaskHUAWEI

New Structures

• Extending PhysicalDeviceFeatures2, DeviceCreateInfo:

  • PhysicalDeviceInvocationMaskFeaturesHUAWEI

New Enum Constants

• HUAWEI_INVOCATION_MASK_EXTENSION_NAME

• HUAWEI_INVOCATION_MASK_SPEC_VERSION

• Extending AccessFlagBits2:

  • ACCESS_2_INVOCATION_MASK_READ_BIT_HUAWEI

• Extending ImageUsageFlagBits:

  • IMAGE_USAGE_INVOCATION_MASK_BIT_HUAWEI

• Extending PipelineStageFlagBits2:

  • PIPELINE_STAGE_2_INVOCATION_MASK_BIT_HUAWEI

• Extending StructureType:

  • STRUCTURE_TYPE_PHYSICAL_DEVICE_INVOCATION_MASK_FEATURES_HUAWEI

Examples

RT mask is updated before each traceRay.

Step 1. Generate InvocationMask.

//the rt mask image bind as color attachment in the fragment shader
Layout(location = 2) out vec4 outRTmask
vec4 mask = vec4(x,x,x,x);
outRTmask = mask;

Step 2. traceRay with InvocationMask

vkCmdBindPipeline(
    commandBuffers[imageIndex],
    VK_PIPELINE_BIND_POINT_RAY_TRACING_KHR, m_rtPipeline);
    vkCmdBindDescriptorSets(commandBuffers[imageIndex],
    VK_PIPELINE_BIND_POINT_RAY_TRACING_NV,
    m_rtPipelineLayout, 0, 1, &m_rtDescriptorSet,
    0, nullptr);

vkCmdBindInvocationMaskHUAWEI(
    commandBuffers[imageIndex],
    InvocationMaskimageView,
    InvocationMaskimageLayout);
    vkCmdTraceRaysKHR(commandBuffers[imageIndex],
    pRaygenShaderBindingTable,
    pMissShaderBindingTable,
    swapChainExtent.width,
    swapChainExtent.height, 1);

Version History

• Revision 1, 2021-05-27 (Yunpeng Zhu)

  • Initial draft.

See Also

PhysicalDeviceInvocationMaskFeaturesHUAWEI, cmdBindInvocationMaskHUAWEI

Document Notes

For more information, see the Vulkan Specification

This page is a generated document. Fixes and changes should be made to the generator scripts, not directly.