"Opposition, that's conspiration."
- Karl XIV Johan, King of Sweden 1818-1844

New demo
Sunday, June 1, 2003 | Permalink

Time for another volumetric lighting demo.

Some nice volumetric lights to look into until you've burned the macula.
The map is the DM-Tutorial map from UT.

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davepermen
Monday, June 2, 2003

looks really pretty. there are some black pixels at edges of some triangles, though..

Humus
Tuesday, June 3, 2003

Use FSAA

davepermen
Tuesday, June 3, 2003

i alway do, hehe

Zeno
Thursday, June 5, 2003

Hey Humus. As always, nice demo!

I hope you don't mind some constructive criticism

One thing I noticed is that it's very dark in the corners of the room. I can just barely see them on my monitor, unless I have a light between me and a dark corner. If this were real, having a bright glaring light between me and a dark object wouldn't help me to see it...just the opposite in fact. The same atmospheric haze that's scattering the light towards the viewer will also diminish the amount of light reaching the viewer from the bakground.

I haven't looked at your shader, but I assume the final per pixel color is done something like this:

final color = backgroundColor + lightColor * lightVolumeThickness

When it should probably be more like this:

final color = (1-lightVolumeThickness) * backgroundColor + lightColor * lightVolumeThickness

Of course, a real atmosphere would probably exhibit more of an exponential decay than a linear one, but I think this would be a simple way to make it much more realistic.

-- Zeno

Humus
Friday, June 6, 2003

Yeah, I've thought about doing something like that. I could also have good use of the sRGB texture reads and writes, though that's not exposed in OpenGL. The non-linearity of the framebuffer makes details in the background become more apparent when you add something on top of it.