[Algorithms] Silhouette determination for the world's shadow volume

[Damian C. <Dam...@m8...>]

Morning,

WRT shadow volumes, what's a common approach for determining the
silhouette for the world mesh?  Let's say it's an indoor only game. In
this case the camera and lights are both "inside" the world mesh, and
the world mesh is concave.

For the other meshes that move around inside the world, silhouette
determination is well documented - "The set of all edges that connect a
toward-face to an away-face form the silhouette with respect to the
light source. The edges forming the silhouette are extruded away from
the light to construct the faces of the shadow volume".

What about the world mesh though? My initial thoughts are to use all
world mesh polygons that don't face the light source, and create
individual shadow volumes for each polygon.  This would get costly if
the world mesh had many back facing polygons at any given time.  How
else is it done?


~Damian();