====== Rendering ======

SimpleRenderer should also provides methods to place lights and set ambient parameters.

===== Classes =====

==== SimpleRenderer ====
This Renders SimpleRenderables, culling them using the given ICuller on the constructor.
The renderer holds a cullcamera and a rendercamera.
NOTE: When a renderable has changed, you must call UpdateRenderable

==== ICuller ====
This currently only poses as a way to implement a Culler that does not cull, used in testing.

==== FrustumCuller ====
This frustum culler stores cullables in the leaf nodes. The visible leaf nodes can be updated. The cullables VisibleReference count is then updated.

==== SimpleBoxMesh, SimpleSphereMesh ====
These are 2 renderables that can be rendered with the SimpleRenderer. They inherit from SphereMesh and BoxMesh to implement the renderer.

==== ICullable ====
An cullable can have its referencecount updated by the culler. Its ReferenceCount represents the number of instances that require the cullable to be visible. When ReferenceCount equals 0 then the cullable is invisible.

==== ISimpleRenderable ====
An object that can be rendered by the SimpleRenderer. Then renderer will only render it when the cullable has deemed it visible.