Ok here’s my solution:
I’m using so-called ‘visibility maps’ in order to achieve soft shadow adges. In fact it isn’t physically correct, but I think it’d work pretty well. The basic approach is to draw the shadower-face into a texture, to soft the edges, to project it onto the other geometry(using automatic texture coords generation) and then, using a GL_ZERO, GL_SRC_COLOR OGL blend mode(or other Multitex stuff)to draw the litten faces onto the already shadowed faces(maybe using per-pixel lighting etc)…
WOW… I hope you got this ) Any comments/ideas?