vkCmdWriteAccelerationStructuresPropertiesKHR

To query acceleration structure size parameters call:

void vkCmdWriteAccelerationStructuresPropertiesKHR(
    VkCommandBuffer commandBuffer,
    uint32_t accelerationStructureCount,
    const VkAccelerationStructureKHR* pAccelerationStructures,
    VkQueryType queryType,
    VkQueryPool queryPool,
    uint32_t firstQuery);

• commandBuffer is the command buffer into which the command will be recorded.
• accelerationStructureCount is the count of acceleration structures for which to query the property.
• pAccelerationStructures is a pointer to an array of existing previously built acceleration structures.
• queryType is a VkQueryType value specifying the type of queries managed by the pool.
• queryPool is the query pool that will manage the results of the query.
• firstQuery is the first query index within the query pool that will contain the accelerationStructureCount number of results.

Accesses to any of the acceleration structures listed in pAccelerationStructures must be synchronized with the VK_PIPELINE_STAGE_2_ACCELERATION_STRUCTURE_COPY_BIT_KHR

pipeline stage or the VK_PIPELINE_STAGE_ACCELERATION_STRUCTURE_BUILD_BIT_KHR

pipeline stage, and an access type of VK_ACCESS_ACCELERATION_STRUCTURE_READ_BIT_KHR.

• If queryType is VK_QUERY_TYPE_ACCELERATION_STRUCTURE_COMPACTED_SIZE_KHR, then the value written out is the number of bytes required by a compacted acceleration structure.
• If queryType is VK_QUERY_TYPE_ACCELERATION_STRUCTURE_SERIALIZATION_SIZE_KHR, then the value written out is the number of bytes required by a serialized acceleration structure.