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LiteFX

LiteFX::Rendering::IGraphicsDevice::computeAccelerationStructureSizes

`LiteFX::Rendering::IGraphicsDevice::computeAccelerationStructureSizes`¶

Computes the required amount of device memory for an IBottomLevelAccelerationStructure.

Synopsis¶

Declared in <litefx/rendering_api.hpp>

[[dllimport, dllexport]] void computeAccelerationStructureSizes(
    IBottomLevelAccelerationStructure const& blas,
    UInt64& bufferSize,
    UInt64& scratchSize,
    bool forUpdate = false) const;

Description¶

Acceleration structures are built on the GPU, which requires additional memory called scratch memory. When creating an acceleration structure (AS), you have to provide a temporary buffer containing the scratch memory, alongside the actual buffer that stores the AS itself. This method can be used to pre-compute the buffer sizes for both buffers.

This method is only supported, if the GraphicsDeviceFeatures::RayTracing feature is enabled.

Parameters¶

Name	Description
blas	The bottom-level acceleration structure to compute the memory requirements for.
bufferSize	The size of the acceleration structure buffer.
scratchSize	The size of the scratch memory buffer.
forUpdate	If set to `true`, `scratchSize` will contain the amount of scratch memory required for an update.