Same goes for Model::IsDrawEnabled() => SceneNode::IsDrawingEnabled()
Is Drawable is now a pure virtual method from SceneNode
Former-commit-id: 217c6a21a98206ee0b283aaa216d419696a70faf
Separated LightManager
Added Sprite class
Added View class
Camera is no longer a SceneNode
Fixed Material not invalidating programs
Renamed CameraPosition uniform to EyePosition
Renamed VisibilityTest to FrustumCull
Former-commit-id: ff7fbe4d9b31a3c269baab0b48c6faa347a12161