Fog

[AReichl]

Hi,
is it possible to create fog that gets denser in one direction?
I fear the answer - "write a shader".

[CuteAlien]

Ah - can't answer - it would scare you.

[AReichl]

Ahh - so scare me.
Is there a solution already?
I would need it for a space scene.
Think of flying into a nebula or the outer region of a giant sun.
Could it be solved with something like "volumetric lighting"?

[mongoose7]

You could simply use parallel transparent planes.

[CuteAlien]

Hm, yeah - a few planes with half-transparent textures could fake it maybe. Thought that would be slow. And for real fog that get's denser with depth and is not regular distributed I think shaders are just the easiest solution. Because I don't think there is a fast way from the fixed function pipeline to access and use the z-buffer in a fast way.

[mongoose7]

What's wrong with world coordinates?

[CuteAlien]

As said - it might work. Would have to experiment how it looks to be sure. But large half-transparent polygons are rather expensive, so I usually try to avoid getting those. And I think a shader for this is just easier. No node handling, no aligning to camera etc... just changing the pixel-color based on the depth of the z-buffer at that point.

[REDDemon]

there's a way to do that in fixed opengl pipeline, but that's a useless functionality since shaders can do more and better (gl fog coord: used to make fog with static geometries like valleys, swamps, mountains.). so no way in irrlicht (no sane engine support gl fog coord). And learn to write shaders it is worth it.