Luvox – Probe Based Realtime GI For URP

Luvox Realtime GI is a lightweight dynamic indirect-lighting solution for Unity URP.

Based on Precomputed Radiance Transfer principles, Luvox bakes scene data into a probe volume in the Editor and updates the indirect-light response at runtime using the active Directional Light.

The result is stable in world space and does not depend on the current camera view. It is designed as a practical and affordable solution for projects that need dynamic ambient lighting without the cost or complexity of a full realtime GI system.

Setup is simple:

- Add the Luvox Probe Volume and Relight Manager components.

- Configure the probe bounds and spacing.

- Bake the probe data.

- Add the included RelightSubGraph to your Shader Graph.

- Connect the Sub Graph output to Emission.

Luvox supports URP Forward and Deferred rendering paths, including mobile platforms.

The package includes an example scene, probe visualization tools, runtime debugging options and documentation.

Mobile support:

- Designed with mobile performance in mind.

- Sparse probe indexing avoids unnecessary runtime sampling and keeps the system lightweight.

- Optional chunk-based updates prioritize nearby probes and spread relighting work across frames.

- Tested with over 100,000 probes while maintaining 100+ FPS on a mobile device.

Current limitations:

- Runtime relighting is driven by one Directional Light.

- Point Lights, Spot Lights and emissive materials do not currently update indirect lighting.

- Static level geometry is baked in the Editor. Geometry changes require a rebake.

- Indoor lighting uses a simplified approximation and may require some tuning.