Advances in path tracing techniques have allowed for the capture of lighting data from the environment, enabling the use of indirect illumination in real-time with both improved accuracy and speed. RTXGI SDK implements two such techniques, replacing traditional probe-based irradiance caching with a world-space radiance cache which can be used to sample outgoing radiance each time scene geometry is hit during path tracing.

These techniques may be combined with a regular path tracing pipeline for the primary rays, sampling cached data only for indirect bounce evaluation. By replacing the whole path trace with a single ray hit evaluation and cache lookup, the cost is reduced with little to no compromise in signal quality, while remaining responsive to change and supporting large-scale dynamic scenes with complex lighting setups.

RTXGI SDK provides an example integration (DX12 and Vulkan) of two state-of-the-art radiance caching techniques for path tracing - a (currently experimental) AI-based approach known as Neural Radiance Cache (NRC), and Spatially Hashed Radiance Cache (SHARC). The former requires Tensor Cores while the latter has certain limitations but is currently supported on a wider range of hardware without any vendor-specific requirements. RTXGI SDK also hosts documentation and distribution corresponding to both of these techniques, see Project Structure section for further details.

Any DXR GPU | CMake v3.24.3 | Git LFS | Vulkan SDK 1.3.268.0 | VS 2022 | Windows SDK ≥ 10.0.20348.0 | Latest driver recommended

• Quick start guide for building and running the pathtracer example.
• NRC integration guide and the SHARC integration guide respectively.
• Change log for release information.

RTXGI SDK is actively being developed. Please report any issues directly through the GitHub issue tracker, and for any information or suggestions contact us at rtxgi-sdk-support@nvidia.com.

Use the following BibTex entry to cite the usage of RTXGI in published research:

@online{RTXGI,
   title   = {{{NVIDIA}}\textregistered{} {RTXGI}},
   author  = {{NVIDIA}},
   year    = 2024,
   url     = {https://github.com/NVIDIAGameWorks/RTXGI},
   urldate = {2024-03-18},
}

See LICENSE.md