C Specification

An acceleration structure has memory requirements for the structure object itself, scratch space for the build, and scratch space for the update.

Scratch space is allocated as a VkBuffer, so for VK_ACCELERATION_STRUCTURE_MEMORY_REQUIREMENTS_TYPE_BUILD_SCRATCH_NV and VK_ACCELERATION_STRUCTURE_MEMORY_REQUIREMENTS_TYPE_UPDATE_SCRATCH_NV the pMemoryRequirements->alignment and pMemoryRequirements->memoryTypeBits values returned by this call must be filled with zero, and should be ignored by the application.

To query the memory requirements, call:

// Provided by VK_NV_ray_tracing
void vkGetAccelerationStructureMemoryRequirementsNV(
    VkDevice                                    device,
    const VkAccelerationStructureMemoryRequirementsInfoNV* pInfo,
    VkMemoryRequirements2KHR*                   pMemoryRequirements);

Parameters

  • device is the logical device on which the acceleration structure was created.

  • pInfo is a pointer to a VkAccelerationStructureMemoryRequirementsInfoNV structure specifying the acceleration structure to get memory requirements for.

  • pMemoryRequirements is a pointer to a VkMemoryRequirements2KHR structure in which the requested acceleration structure memory requirements are returned.

Description

Valid Usage (Implicit)

  • VUID-vkGetAccelerationStructureMemoryRequirementsNV-device-parameter
    device must be a valid VkDevice handle

  • VUID-vkGetAccelerationStructureMemoryRequirementsNV-pInfo-parameter
    pInfo must be a valid pointer to a valid VkAccelerationStructureMemoryRequirementsInfoNV structure

  • VUID-vkGetAccelerationStructureMemoryRequirementsNV-pMemoryRequirements-parameter
    pMemoryRequirements must be a valid pointer to a VkMemoryRequirements2KHR structure

See Also

VK_NV_ray_tracing, VkAccelerationStructureMemoryRequirementsInfoNV, VkDevice, VkMemoryRequirements2KHR

Document Notes

For more information, see the Vulkan Specification

This page is extracted from the Vulkan Specification. Fixes and changes should be made to the Specification, not directly.

Copyright

Copyright 2014-2024 The Khronos Group Inc.

SPDX-License-Identifier: CC-BY-4.0