vkGetAccelerationStructureMemoryRequirementsNV

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:

void vkGetAccelerationStructureMemoryRequirementsNV(
    VkDevice device,
    const VkAccelerationStructureMemoryRequirementsInfoNV* pInfo,
    VkMemoryRequirements2KHR* pMemoryRequirements);

• 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.