- Since Radiant GI is a screen-space effect, it cannot use emissive or lighting coming from objects that are not actually visible on the screen in an accurate way unless you enable some of the fallbacks (see dedicated section). When you move the camera around, you can see a fluctuation of the indirect illumination when bright objects leave or enter the camera frustum. This is by design in all techniques based on screen space effects. If this is a problem in your scene, enable one or more fallbacks or reduce the intensity of the effect or disable it completely in that area of your scene (use multiple post processing volumes to adjust it to the requirements of each area if needed).
- Deferred rendering path is recommended. In this mode, Radiant will use the albedo and specular data from the g-buffers to produce a more accurate result. Forward rendering will still work but the indirect light cast on very dark objects will make them look “whitish”. Use the Luma Influence setting in forward rendering mode to boost dark pixel colors.
- Performance: a balanced configuration includes the following settings (like the Atrium demo scene):
- Indirect Intensity = 1-3
- Ray Count = 1 (increasing ray count can be expensive).
- Max Distance = 8.
- Max Samples = 24.
- Thickness = 0.1-0.3.
- Raytracer Accuracy = 8 (reducing accuracy can improve performance).
- Downsampling = 1 (increase to improve performance).
- Reuse Rays = 0-0.5.
- Temporal Stabilization = 8-12
- Temporal Response Speed = 12
Important: Radiant is an indirect lighting provider. It’s not intended to replace usual direct lighting. The asset is intended to add more realism to the scene where direct lighting can’t reach (ie. shadowed areas). We suggest that you reduce the Unity Ambient Lighting slider value and increase the APV/Sky fallback. Also increasing source brightness in the indirect section will improve the impact of the overall effect.
