Light decals...need help... +Halo's explanation

Blitz3D Forums/Blitz3D Programming/Light decals...need help... +Halo's explanation

I mean a basic dynamic real time lighting
effect... like that in Unreal or Quake...
A decal appears on the map (circle of light)
Then that decal subtracts away from the shadows
created by the light map.... Just for Mapping...
Not for charecters... I understand that would be slow as all hell...
So I'd just use vertex lighting for them... Never mind that though...
The decal would be used for gun flashes and other
lighting... Does NE one know how to acheive this?
I'm sure BLITZ3d can acheive this somehow.....
I'm getting stressed trying to find out though....
Please help...