The latest version of NVIDIA VXGI 0.9 is now available for download from here. NVIDIA VXGI is an implementation of a global illumination algorithm known as Voxel Cone Tracing. Global illumination computes all lighting in the scene, including secondary reflections of light of diffuse and specular surfaces. Adding GI to the scene greatly improves the realism of the rendered images. Modern real-time rendering engines simulate indirect illumination using different approaches, which include precomputed light maps (offline GI), local light sources placed by artists, and simple ambient light. NVIDIA VXGI 0.9 provides a global illumination example as well as an ambient occlusion example. VXGI is integrated into our UE4 GitHub branch.

Release Notes for 0.9:

  • Initial release featuring diffuse and rough specular indirect lighting, with support for arbitrary dynamic scenes and area lights.
  • Supports Direct3D 11 only, but does not require any vendor-specific hardware features, works on any D3D11 capable hardware.
  • There are some known issues with image quality, specifically:
    • Flickering can sometimes be observed when lit objects are moving uniformly;
    • The intensity of light cast by small area lights can change when the camera moves towards or away from such lights;
    • Diffuse illumination on geometry with lots of fine detail can be observed with some static screen-space noise, especially if diffuse illumination is computed with high sparsity;
    • Reflections rendered with VXGI specular tracing are always blurry. VXGI cannot render perfect-mirror reflections.
  • Memory requirements can be adjusted between about 15 MB to 2.5 GB, with more expensive options taking more time to process and producing higher quality results.


Byzantos demonstrated what can be done with NVIDIA's VXGI technology in UE4. The results are amazing! We value the feedback and are working on improving this beta technology. Read more ...