Allow zooming while rotating (OrbitControls)

[BroHammie]

Significantly older version of OrbitControls allowed for zooming while rotating. Hoping we can add this back in.

[WestLangley]

How do you manage to zoom and rotate the camera at the same time?

[BroHammie]

Hold down the the left mouse button and then operate the mouse wheel(while left button is still down).
webgl_buffergeometry_drawcalls.html is a good example to test the changes.

[WestLangley]

Hmmm... One can't do that on a Mac.

Also, wouldn't that lead to different behavior between a touch device and a mouse?

[BroHammie]

This would have no impact on the touch devices as touch devices call into the onTouchStart function. And only have 1/2/3 finger functions, I am assuming similar to a Mac device.

[WestLangley]

Right. That results in different behaviors: you could scroll and zoom simultaneously with a PC, but not a touch device, and not a Mac.

Just stating the implications of this PR so it is clear -- not passing judgement.

[MasterJames]

I with limited weight here would say don't let the weak links limit those with more ability and so I would say disabling functionality because other people can't handle or achieve it is not the right way forward. "Let them catch up if they can."
What about zoomimg in VR/AR? Certainly there's ways to do both with various tools. With that said and with open source in mind, Orbit Controls etc. is not the only way one can make variations as needed so it really doesn't matter to coders with open source.

[mrdoob]

Thanks!