- Mar 25, 2012
What i am talking about is mostly penumbra and umbra.
It is possible to have that without raytracing (and a bunch of games already have it), e.g. here is a screenshot of my engine from a year ago when i first added it:
However it has several drawbacks, main being that it only works with lights whose area can be expressed as a distance from the lightsource itself (e.g. sphere-shaped where the lightsource is a point light and the distance is the sphere's radius). And of course all the drawbacks it inherits from shadowmapping in general, like aliasing, peter panning, shadow acne, etc.
IMO while GI is nice, the biggest feature for raytracing is shadows that actually work without ghastly hacks on shadowmapping.