Experimental Volumetric Light

Cactus on Fire

Hey. I was playing around with max and came up with this method for faking volumetric light. It uses a mix of gradient and falloff for opacity map and a flat self-illumination color, applied to a geosphere. I just took a raw render of the result, this is exactly what it would look like in-game.

It has limitations such as the sphere cutting off when its near an object, and giving bad results if you stretch the sphere in one direction, but you can work around it by applying the elongated sphere a normalmap of a straight sphere. But overall, I think it gives a decent result.

Just wanted to share it, comments and suggestions are welcome.

EmAr

This looks good. How about re-creating it in UDK or Unity? That could be more advantageous to include in a demoreel.

Cactus on Fire

EmAr wrote: »

This looks good. How about re-creating it in UDK or Unity? That could be more advantageous to include in a demoreel.

Thanks. I don't know much about unity or UDK, but it will work on any application that supports falloff + mix channel + illumination maps

WadeWT

Reminds me of this: http://simonschreibt.de/gat/doom-3-volumetric-glow/
Pretty neat trick.

Computron

cool

Cactus on Fire

Thanks. I kinda made something for directional light as well, It slowly fades as you look at it directly and avoids clearcut edges, but it gives funny results from certain angles, which is mostly because of the cone shape.

Obscura

Cool, but its a little hard to work with it. I tried it out in UDK with an inverse fresnel/square root/power/glow nodes, and the sphere mesh gave bad look from the side view. Also, I noticed that the effect is not that visible if there are other textured objects behind the lamp/volumetric light. For your presentations: showing it in a scene would be better in my opinion, because it would show how it looks in an actual scene, where there are objects/textured surfaces/shadows.

The cone shaped light is also not bad. I can imagine that it could be better with more layers of cones.

Cactus on Fire

Made a few more tests. The directional don't seem bad but it needs a special operation like softening smoke sprites where they meet the mesh to get rid of the clipping.