-A Pipeline is also a Renderable itself. Externally, it only exposes the
-default pass. Internally, it can hold any number of passes, which are invoked
-in sequence when rendering the default pass is requested. Each pass can have a
-Lighting, a DepthTest and a Blend to control how it is rendered.
+A Pipeline contains a sequence of passes. Each pass has a Renderable along
+with Lighting, Clipping, DepthTest and Blend states. Scenes can be used to
+organize Renderables within a pass. A Camera can be specified for the entire
+Pipeline.
+
+A Pipeline is also a Renderable itself. It will only respond to the default
+pass. The Renderables within the Pipeline will be invoked with whatever tags
+were specified when adding them.