SSR SSAO SSIL SDFGI / Godot4 post processing

https://docs.godotengine.org/en/stable/tutorials/3d/environment_and_post_processing.html

Screen-Space Reflections (SSR) 
While Godot supports three sources of reflection data (Sky, ReflectionProbe, and GIProbe), 
they may not provide enough detail for all situations. 
Scenarios where Screen Space Reflections make the most sense are when 
objects are in contact with each other (object over floor, over a table, floating on water, etc).
The other advantage (even if only enabled to a minimum), 
is that it works in real-time (while the other types of reflections are pre-computed). 
This can be used to make characters, cars, etc. reflect on surrounding surfaces when moving around.

Screen-Space Ambient Occlusion (SSAO)
its purpose is to make sure concave areas are darker, simulating a narrower path for the light to enter
SAO only acts on ambient light, not direct light.
If you want to force SSAO to work with direct light too, use the Light Affect parameter (even though this is not correct, some artists like how it looks).
SSAO looks best when combined with a real source of indirect light, like GIProbe  (godot4에서 GIProbe는 VoxelGI로 대체)

Screen Space Indirect Lighting (SSIL)
빛의 바운스를 부드럽게 하거나 추가해줘서 빛의 반사 부분이 전체적으로 풍부해진다.https://www.youtube.com/watch?v=KH8qgPIGVmY

 

Signed Distance Field Global Illumination (SDFGI)

SDFGI is something akin to a dynamic real-time lightmap (but it does not requiere unwrapping, nor does it use textures). It's enabled and it automatically works by generating global illumination for static objects. It does not require raytracing, and it runs in most current (and some years old) dedicated GPUs, even medium-end budget CPUs from some years ago (SDFGI was developed and tested on a GeForce 1060, running at a stable 60 FPS).

Light changes are real-time, meaning any change in lighting conditions will result in an immediate update. Dynamic objects are supported only for receiving light from the environment, but they don't contribute to lighting. Some degree of support is planned for this eventually, but not immediately.

 

*SDFGI + SSAO + SSIL 로 기본 환경을 세팅하면 무난할 듯 하다.