Render shadow volume (sides and caps) of this scene, for shadow volume algorithm. Uses ShadowVolumeRenderer for rendering, and to detect if rendering is necessary at all. It will calculate current bounding box (looking at ParentTransform, ParentTransformIsIdentity and LocalBoundingBox method).
It always uses silhouette optimization. This is the usual, fast method of rendering shadow volumes. Will not do anything (treat scene like not casting shadows, like CastShadowVolumes = false) if the model is not perfect 2manifold, i.e. has some BorderEdges (although we could handle some BorderEdges for some points of view, this could leading to rendering artifacts).
All shadow quads are generated from scene triangles transformed by ParentTransform. We must be able to correctly detect front and back facing triangles with respect to light position, so ShadowVolumeRenderer.LightPosition and "this scene transformed by ParentTransform" must be in the same coordinate system. If ParentTransformIsIdentity then ParentTransform value is ignored and everything works like ParentTransform = identity matrix (and is a little faster in this special case).
Uses TrianglesListShadowCasters and ManifoldEdges and BorderEdges (so you may prefer to prepare it before, e.g. by calling PrepareResources with prShadowVolume included).
We look at some Attributes, like Attributes.Blending, because transparent triangles have to be handled a little differently, and when Attributes.Blending = false then all triangles are forced to be opaque. In other words, this takes Attributes into account, to cooperate with our Render method.
ShadowVolumeRenderer.LightPosition is the light position. ShadowVolumeRenderer.LightPosition[3] must be 1 (to indicate positional light) or 0 (a directional light). It's expected that ShadowVolumeRenderer is already initialized by ShadowVolumeRenderer.InitFrustumAndLight.
Faces (both shadow quads and caps) are rendered such that CCW <=> you're looking at it from outside (i.e. it's considered front face of this shadow volume).
