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Volume lightmapping demo
Tuesday, March 2, 2004 | Permalink

With a loud thud another demo hits the site. Go fetch in the 3D section.



Enter the code below

Friday, March 5, 2004

Cool demo !

The main drawback of this technique - in my opinion - is that the use of a 3D texture waste lot of memory compared to a "shadow cube-map".
Moreover the only relevant information is where the surface intersects the texture (ok, with dynamic moving objects in the scene it makes sense to have lighting information defined everywhere :-)

The softness obtained looks great. I guess it mainly comes from the linear interpolation - doesn't it produce some artefacts (i.e. thin objects wrongly shadowed) ? (unfortunately I can't run the demo ...)

However I don't think fog can be handled with good performances : It would require to render "the light volume" i.e. to render some front facing polygons (=> bad for fillrate since these polygons will cover the whole screen).
Hmmm ... it may be worth the try ;-)

Anyway, thanks for all these cool effects !

Friday, March 5, 2004

yes, that could certainly be done.

yes, coloring the light when in passed through glass could be done too. You'd need to go to at least 16bit color though, so that's twice the size, but it could maybe be worth it. There's a lot of things you could encode into a static texture like this. I came to think of an optimisation I overlooked. Right now I'm doing attenuation in the shader. But that could be baked into the lightmap instead. Should improve performance.

the softness comes from true soft shadow calculation rather than from linear filtering. For each point I evaluate 100 samples within a light volume roughly the size of the fire and average it.

Sunday, March 7, 2004

very nice. would be cool to have some sort of transparent slide going trough the volume "scanning it".. to show more what its all about..

oh, and the ufo should get a (projected..) shadow..

and i explained you yet that we need henriks smoke and fire, of course..

oh, and do you do full global illumination? again, henrik can help you

bah.. it's a great demo the way it is. it looks impressive.

Monday, March 8, 2004

does not work with GFFX series cards.

Please redo to include support for geforce cards. I have tried to enter the enteries in the registry, but on 98 there is no "debug" key in the registry. adding one and entering the Dword strings does not help either. I dont mean any offense, but I dont like ATi and I will never use their products.

Monday, March 8, 2004


The problem is not with Humus's demo at all, but nvidia's lack of official support for HLSL. The registry hack is the only way to enable the work-in-progress implementation in current drivers. Humus's demo uses GLSL because that's the future of OpenGL shading. Nvidia not bringing GLSL to the table fast enough is not Humus's fault, nor should he have to worry about it for a demo that he wrote in his spare time to share with the entire world for FREE. We're sorry you don't like ATI's products (starting to think the whole point of your post was to make that very statement) but Humus should not have to 'redo' HIS software to cater to YOUR needs. Live with it.

BTW, Humus, great demo as usual. Keep up the great work! I for one, am grateful for what you are doing for the graphics development community.

Tuesday, March 9, 2004

I still can't get the thing to work on my GFFX5600, registry hack or no.

Tuesday, March 9, 2004

Make sure you got a recent enough driver. I don't know the number, but I think it's only the latest leaked driver that has GLSL support.

Friday, March 12, 2004

@Humus: Great Work

@sephox: You need at least the Forceware 56.56 Driver to enable GLSL on your GeForce FX.

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