In the Showdown demo there is an ExplosionGlow material which is applied to an inversesphere mesh to effectively simulate a simple point light (unshadowed diffuse normal lighting only). The material is translucent, unlit with “Disable Depth Check”. The inverse sphere mesh basically is just a way to mask which pixels should be affected and it’s origin is used as the origin of the “light” in the material calculations.
Despite 3 big explosions in the demo there seems to be only one use of this in the demo as released (around the fire-hydrant explosion near the start) . There are references to it being used in muzzle flash effects but that seems to have been turned off. Finally there seems to be a movable point light at the same location.
So why was this used and only used once? Is this technique significantly better performing than a non-shadowing movable point light? Why was it disabled elsewhere as released?