Not yet 100% sure about all the details but this is something that should be useful for making helpers prettier.

This makes it safer to compile shaders without maxLights cap. Only per vertex phong code path is sensitive to available number of varyings (together with shadow maps, but you would need to be pretty crazy to have enough shadowed lights to hit varying limits).

Also like this phong material behaves more as expected for large polygons.

Performance wise, for many use cases and systems it's actually similar or even faster.

It's now up to the application layer to deal with system specific shader limits.

Fixes #2477

Update doc with latest method names.

Fixes #2581

Fixes #2577

Extra check doesn't seem to have much effect on performance. This may become a bigger concern if other bottlenecks would go away.

Fixes #2568

Don't need to update scene graph matrices (molecules don't change).

This has very little impact on performance though, bottleneck is not on JS side, profiler shows ~65% of time spent in "(program)".

Maybe these should be toggleable, they are too slow for larger molecules.

It seems no matter which DOM elements are used for CSS 3D, you can't have more than couple hundreds without starting to hit a performance wall, even on desktop browsers ;S

This was causing vortex-looking bug when panning camera with TrackballControls on right click drag.