Official tutorial redshift 03 parameters and general instructions of various GI

1、Photons map Photon mapping
Photons map Setting instructions ：

Reflection Tracing Depth 10: The number of reflections per pixel is the number of rays ;

Refrection Tracing Depth 10: The number of refraction bounces per pixel is the number of rays ;( If there is no refraction type material in the scene, you can give 0)

Max Num GI Photons： Diffuse reflection GI The upper limit of the number of photons in the search radius of the shaded pixel , It is recommended to default ;

GI Search Radius ： Diffuse reflection GI The distance from the shaded pixel to search for nearby photons ;

Max Num Caustics Photons : Caustics GI The upper limit of the number of photons in the search radius of the shaded pixel , It is recommended to default ;

Caustics Search Radius : Caustics GI The distance from the shaded pixel to search for nearby photons ;

Diffuse reflection should be turned on in the light attribute GI And caustics GI,Photons to Emit Determines the number of photons in the whole scene ;

Caustic effect needs to meet three conditions at the same time (IPR I won't support it ,Render Support )：
1、Photons map Photon mapping engine ;
2、 The model turns on caustics ;
3、 Light turns on caustics ;

2、Brute Force GI Violent way

Generally, as the first level GI Use , Level 2 generally uses radiant point clouds （ Light cache ） In combination with

Num Rays The general advice is 256-512;

Min Samples commonly 8

Max Samples commonly 64-128-256 coordination Adaptive Eeeor Threshold 0.002-0.006-0.012

3、Irradiance Caching Radiation cache

The advantages are summarized above ;





Color Threshold/Distance Threshold/Normal Threshold Three very important threshold parameters

If you don't know or worry about the uncontrollable effect caused by misoperation, use the default Medium Just go ;










Suggestions for 0, Don't let it participate in any fuzzy effect , Make rendering more accurate ;

Noise reduction needs analysis ：

1、 Light sampling ;（ After the test, it is found that the impact is small and can be appropriately reduced , Faster rendering time ）
2、 Reflection sampling ;（ After the test, it is found that the impact is small and can be appropriately reduced , Faster rendering time ）
3、 Refraction sampling ;（ After the test, it is found that the impact is small and can be appropriately reduced , Faster rendering time ）
4、 The renderer output is uniformly sampled ;（ Motion blur or depth of field is also controlled here – After the test, it is found that the impact is small and can be appropriately reduced , Faster rendering time ）
5、SSS（ If there is ） Sampling can be adjusted appropriately according to the effect ;（ After the test, it is found that the impact is small and can be appropriately reduced , Faster rendering time ）
6、 Class A GI engine ;Num Rays/Adaptive Amount/Adaptive Error Threshold Parameters can be reduced and details adjusted ;

4、Irradiance Point Cloud Radiant point cloud