That Black Light demo - anyone know how it works?

As the title really, all the forum links to the demo zip are gone, and I can't seem to figure out how these negative lights and fog give that visual effect.

Does it not use a negative near value for the fog as well? I'm not quite sure myself tbh. But i think it's all to do with the fogging.

I've tried negative fog but I just can't get it right.

I think I remember. Was that the one by big10p or big&? Any idea what the file is called as I have loads of saved demo's on my drives.

Were the entities themselves not set with difuse negative color too?

This produces a black light. I'm not quite sure what the orginal effect looked like now...

Graphics3D 800,600
SetBuffer BackBuffer()

light = CreateLight()
LightColor light,-255,-255,-255
TurnEntity light,0,40,0

camera = CreateCamera()
PositionEntity camera,0,0,-2

s = CreateSphere()
EntityColor s,128,128,128


;CameraFogMode camera,1
;CameraFogRange camera,-100,100
;CameraFogColor camera,-255,0,0


While Not KeyHit(1)




	UpdateWorld
	RenderWorld
	Flip
Wend

It could be an interesting idea for a shadow engine :o) Don't know how that would work though.

You can get the exe here:
http://www.geocities.com/blitzmirror/

I think the source was released at some point, you could try contacting Big&.