mrdoob/three.js — pull request #5629 by m-schuetz (2014-11-14 15:58:32+00:00)
Title: added PerspectiveCamera.zoomTo()

I've done this a while ago and thought it might be useful to have this in three.js itself.
This function moves the camera so that it fits the bounding box of the given object.

Here's a demo: http://potree.org/stuff/threejs/camera_zoomto/examples/webgl_camera_zoomto.html