Hello everyone, I'm currently trying to implement the accurate atmospheric scattering technique of Sean O'Neil (GPU Gems 2). I now have something that resembles a sky, but with some issues. First of all, O'Neil mentions that the radius of the atmosphere for a planet is 2.5% of the radius of a planet. When using the SkyFromAtmosphere shader I have a black sky when I keep to that ratio, but when the innerradius is very small and the outerradius is very large it works fine. Second, If I have the sun in the east, the sky looks good there, but in the west it's completely black. I never have my complete skydome colored, there's always some black region somewhere... So the question is if anyone has an idea what causes these issues? Is it a setting, could it be some obvious mistake in the shader? To illustrate two screenshots: This is where I see the sky quite nicely, but if I turn the camera 180 degrees I see utterly black. On the right you can see the different settings. (scale depth is divided by 100, Sun color and spec lvl are not used) This is a screenshot with the sun at the horizon, also not quite correct I think.

Thanks for the reactions! They quite helped.

The solution to my problem was: keep to the values used by O'Neil. The (of course) 102.5% outer radius and the 1/4 of the atmosphere thickness as value for the scale depth did the trick. Indeed, these ratios are neccessary for the scale function.

Lex