powerpad

05-23-2005, 11:26 AM

When I want to draw a capped shadow volume

I proceed as outlined by lengyel in his article

for a silhouette edge I do..

1. take all vertices from a triangle that faces towards the light

2. extrude all vertices from a triangle that faces away from the light to infinity with respect to the light direction

Until now I add those vertices into my List of vertices making up the silhouette ...

but It is said that the shadow volume should be closed should I therefore insert the vertices in such a way that I get some polygon formed by the front cap, back cap and sideplanes closing the front and back cap

or is it totally sufficient to inseert the vertices to have a triangle that represents the front cap and the vertices to have a back cap.

tnx for your help

I proceed as outlined by lengyel in his article

for a silhouette edge I do..

1. take all vertices from a triangle that faces towards the light

2. extrude all vertices from a triangle that faces away from the light to infinity with respect to the light direction

Until now I add those vertices into my List of vertices making up the silhouette ...

but It is said that the shadow volume should be closed should I therefore insert the vertices in such a way that I get some polygon formed by the front cap, back cap and sideplanes closing the front and back cap

or is it totally sufficient to inseert the vertices to have a triangle that represents the front cap and the vertices to have a back cap.

tnx for your help