Skybox support?

[louisGreenland]

Great work! Is it possible to get some sort of skybox support with this atmospheric scattering effect?

[simeonradivoev]

It should be easy, given that the scattering is just a post-processing effect. Does it not work with Unity's Skybox system?

[simeonradivoev]

Ah it seems the skybox is rendered after lighting. So for skybox support to be added, the atmospheric scattering needs to be turned into an effect for the post-processing stack.

[louisGreenland]

I was literally just about to post that haha. I wouldn't know how to go about doing that since I am not at all a shader expert. Another issue seems to be the effect glitching at long distances, not sure if this is a floating point issue that could be solved with a floating origin method but I thought i'd let you know anyways. Great stuff!

[adellari]

@louisGreenland The floating point issues are caused by these lines in AtmosphericScatter.shader:

     float3 attenuation;
     float irradianceFactor = 0;
     float3 inscat = GetInscatteredLight(wpos,viewDir,attenuation,irradianceFactor);
     float3 reflected = GetReflectedLight(wpos, depth,attenuation,irradianceFactor, normal,surfaceColor);

where attenuation is used without proper initialization.
This can of course be easily fixed by changing the first line to

float3 attenuation = float3(0., 0., 0.);

thus removing the visual artifacts

[adellari]

Ah it seems the skybox is rendered after lighting. So for skybox support to be added, the atmospheric scattering needs to be turned into an effect for the post-processing stack.

Alternatively, using a custom skybox shader with blending mode

Blend One One 

works like a charm since the image effect's blending in AtmosphericScattering.shader is

OneMinusSrcAlpha

[dev-bre]

@adellari can you please expand how to fix this?
I am not expert in shaders, but I am trying to have the sun properly rendered in the sky.
Any chance you can provide an example of custom skybox which would work?