Computation times

00:16.361 total execution time for 7 files from examples/04-lights:

Example	Time	Mem (MB)
Shadows (shadows.py)	00:05.230	0.0
Plotter Lighting Systems (plotter_lighting.py)	00:04.997	0.0
Light Types (light_types.py)	00:01.845	0.0
Disabling Mesh Lighting (mesh_lighting.py)	00:01.349	0.0
Beam Shape (beam_shape.py)	00:01.243	0.0
Light Actors (light_actors.py)	00:00.893	0.0
Attenuation (attenuation.py)	00:00.803	0.0