beta patch atmosphere & lighting at altitude

[adonys]

problem with the current patch haze is that, beside the fact it is too heavy, is applied as an overall screen post processing effect.

if you don't know what that is, I'll spell it for you: the whole screen is rendered, and then a new color filter is applied on the whole image before sending it to display.

an atmospheric haze can NOT be represented like that, as closer objects appear almost clear, while haze thickens the further an object is. this can be still computed well for objects (as when checking if they are in view's frustrum, you also check for their distance from the camera, and could apply different color filter effects on groups of them, and only then add them into the scene), even if still compute heavy, but can't really be done for the ground (as you'll need a gradual color filter for a single mesh object which needs to also be view dependant if you choose to apply it as a whole scene effect - as you can't really check for each triangle's distance, or per mesh patches).