Soft Shadows

Hey guys

Do you know any FAST rendering method for soft shadows?

Actually, that’s what I could think of:

Since I’m using a portal based angine, I can determine which area the player is currently in. Then I can get all the portals connected to this area(which lead into other areas), and then make a sort of frustum- the f. sides are going through the portals sides(hope that isn’t too hard to understand

Then, since every face in the world has a lightmap, I’m just projecting every portal frustum onto the ligmap, and then, using a kind of scanline algo, I just draw the portal’s shape into the lighmap and fill it with the computed light values.

Then I’m just rendering the faces as if they had normal lighmaps…

Do you have any other ideas???

I’m working now with method like that. And I think that it’s the best variant when using portal based engine. Only one bottleneck (at least for me now) - how to calculate intensity for every point in lightmap for lightfrustum projection FAST? The brute force method is to calculate [x,y,z] for every [lu,lv] and then calculate the distance from this point to the lightsource. But it’s slow. Any ideas???
P.S. I’m NOT project frustum to LMap, I clip face by frustum in [x,y,z] and [Lu,Lv] space - got the poly which lit completely.
P.P.S. Did you need other (slower possibly) ideas ???