VK_NV_partitioned_acceleration_structure

Other Extension Metadata

Last Modified Date

2025-01-09

Contributors

• Vikram Kushwaha, NVIDIA
• Eric Werness, NVIDIA
• Christoph Kubisch, NVIDIA
• Jan Schmid, NVIDIA
• Pyarelal Knowles, NVIDIA

Description

With an increase in scene complexity and expansive game worlds, the number of instances has surged in ray tracing over the last few years. The current Top Level Acceleration Structure (TLAS) API necessitates a full rebuild of the entire data structure even when only a few instances are modified.

This extension introduces Partitioned Top Level Acceleration Structures (PTLAS) as an alternative to the existing TLAS. PTLAS enables the efficient reuse of previously constructed parts of the acceleration structure, resulting in much faster build times and supporting a higher number of instances.

New Commands

• vkCmdBuildPartitionedAccelerationStructuresNV
• vkGetPartitionedAccelerationStructuresBuildSizesNV

New Structures

• VkBuildPartitionedAccelerationStructureIndirectCommandNV
• VkBuildPartitionedAccelerationStructureInfoNV
• VkPartitionedAccelerationStructureInstancesInputNV
• VkPartitionedAccelerationStructureUpdateInstanceDataNV
• VkPartitionedAccelerationStructureWriteInstanceDataNV
• VkPartitionedAccelerationStructureWritePartitionTranslationDataNV
• Extending VkPartitionedAccelerationStructureInstancesInputNV:
  • VkPartitionedAccelerationStructureFlagsNV
• Extending VkPhysicalDeviceFeatures2, VkDeviceCreateInfo:
  • VkPhysicalDevicePartitionedAccelerationStructureFeaturesNV
• Extending VkPhysicalDeviceProperties2:
  • VkPhysicalDevicePartitionedAccelerationStructurePropertiesNV
• Extending VkWriteDescriptorSet:
  • VkWriteDescriptorSetPartitionedAccelerationStructureNV

New Enums

• VkPartitionedAccelerationStructureInstanceFlagBitsNV
• VkPartitionedAccelerationStructureOpTypeNV

New Bitmasks

• VkPartitionedAccelerationStructureInstanceFlagsNV

New Enum Constants

• VK_NV_PARTITIONED_ACCELERATION_STRUCTURE_EXTENSION_NAME
• VK_NV_PARTITIONED_ACCELERATION_STRUCTURE_SPEC_VERSION
• VK_PARTITIONED_ACCELERATION_STRUCTURE_PARTITION_INDEX_GLOBAL_NV
• Extending VkDescriptorType:
  • VK_DESCRIPTOR_TYPE_PARTITIONED_ACCELERATION_STRUCTURE_NV
• Extending VkStructureType:
  • VK_STRUCTURE_TYPE_BUILD_PARTITIONED_ACCELERATION_STRUCTURE_INFO_NV
  • VK_STRUCTURE_TYPE_PARTITIONED_ACCELERATION_STRUCTURE_FLAGS_NV
  • VK_STRUCTURE_TYPE_PARTITIONED_ACCELERATION_STRUCTURE_INSTANCES_INPUT_NV
  • VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PARTITIONED_ACCELERATION_STRUCTURE_FEATURES_NV
  • VK_STRUCTURE_TYPE_PHYSICAL_DEVICE_PARTITIONED_ACCELERATION_STRUCTURE_PROPERTIES_NV
  • VK_STRUCTURE_TYPE_WRITE_DESCRIPTOR_SET_PARTITIONED_ACCELERATION_STRUCTURE_NV

Version History

• Revision 1, 2025-01-09 (Vikram Kushwaha)
  • Initial draft