Capping Shadow Volumes

OpenGL OpenGL: Advanced Coding
1

In my out-door environment I want to put a end to my shadow volumes, because I don’t want them to throw shadows on my sky-box and for view-frustum clipping.
This is quite difficult because I have lots of unsorted points from my silhouette edges and have to put a polygon on them ( this polygon can be complex, concav and with holes ). I tried to sort and use glu-tesselation, which doesn’t work yet and is slow anyway.
It’s probably better to project my caster-geometrie from 3D in 2D on a plane, just like an easy shadow algorithm !?

I hope you got the point. I’d be glad about any tips or suggestions.

2

you should do it like this -
for every polygon, save its neighbour polygons. and then, when drawing your sil edges, draw your model to the stencil buffer too, draw it’s front facing polys(to the light) where they are, and the others, those which face away from the light, extend just like you extend the sil edges.

3

Draw the sky box once, with no tests etc. Don’t include it in the shadow passes or depth buffer for the stencil pass.

So long as your volumes are bigger than the scene you’ll be in good shape.