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# D3D12_RAYTRACING_ACCELERATION_STRUCTURE_POSTBUILD_INFO_SERIALIZATION_DESC (XBOX Series consoles)

> Describes the size and layout of the serialized acceleration structure and header.

Describes the size and layout of the serialized acceleration structure and header

## Syntax

```cpp theme={null}
typedef struct D3D12_RAYTRACING_ACCELERATION_STRUCTURE_POSTBUILD_INFO_SERIALIZATION_DESC
{
    UINT64 SerializedSizeInBytes;
    UINT64 NumBottomLevelAccelerationStructurePointers;
} D3D12_RAYTRACING_ACCELERATION_STRUCTURE_POSTBUILD_INFO_SERIALIZATION_DESC
```

### Members

*SerializedSizeInBytes*\
Type: UINT64

The size of the serialized acceleration structure, including a header.  The header is [D3D12\_SERIALIZED\_RAYTRACING\_ACCELERATION\_STRUCTURE\_HEADER](/reference/graphics/d3d12/structs/d3d12_serialized_raytracing_acceleration_structure_header_public) followed by followed by a list of pointers to bottom-level acceleration structures.

*NumBottomLevelAccelerationStructurePointers*\
Type: UINT64

The number of  64-bit GPU  virtual addresses that will be at the start of the serialized acceleration structure, after the [D3D12\_SERIALIZED\_RAYTRACING\_ACCELERATION\_STRUCTURE\_HEADER](/reference/graphics/d3d12/structs/d3d12_serialized_raytracing_acceleration_structure_header_public).  For a bottom-level acceleration structure this will be 0.  For a top-level acceleration structure, the pointers indicate the acceleration structures being referred to.

When deserialization occurs, these pointers to bottom-level pointers must be initialized by the app in the serialized data (just after the header) to the new locations where the bottom level acceleration structures will reside.  It is not required that these new locations to have already been populated with bottom-level acceleration structures at deserialization time, as long as they are initialized with the expected deserialized data structures before being used in raytracing.  During deserialization, the driver reads the new pointers, using them to produce an equivalent top-level acceleration structure to the original.

## Requirements

**Header:** d3d12\_xs.h\
**Library:** d3d12\_xs.lib\
**Supported Platforms**: XBOX Series consoles


## Related topics

- [D3D12_RAYTRACING_ACCELERATION_STRUCTURE_POSTBUILD_INFO_CURRENT_SIZE_DESC (XBOX Series consoles)](/reference/graphics/d3d12/structs/d3d12_raytracing_acceleration_structure_postbuild_info_current_size_desc_public.md)
- [D3D12_RAYTRACING_ACCELERATION_STRUCTURE_POSTBUILD_INFO_COMPACTED_SIZE_DESC (XBOX Series consoles)](/reference/graphics/d3d12/structs/d3d12_raytracing_acceleration_structure_postbuild_info_compacted_size_desc_public.md)
- [D3D12_RAYTRACING_ACCELERATION_STRUCTURE_POSTBUILD_INFO_TOOLS_VISUALIZATION_DESC (XBOX Series consoles)](/reference/graphics/d3d12/structs/d3d12_raytracing_acceleration_structure_postbuild_info_tools_visualization_desc_public.md)
- [D3D12_RAYTRACING_ACCELERATION_STRUCTURE_POSTBUILD_INFO_DESC](/reference/graphics/d3d12/structs/d3d12_raytracing_acceleration_structure_postbuild_info_desc_public.md)
- [D3D12_RAYTRACING_INSTANCE_DESC (XBOX Series consoles)](/reference/graphics/d3d12/structs/d3d12_raytracing_instance_desc_public.md)