3D viewer hints: Mouse wheel and middle mouse button zooms (well, dollies - let's be technically correct). Right mouse and three-fingered drag orbits. Control key swaps pan and orbit control. Arrow keys also pan.
Source code here.
3D viewer built on Ricardo Cabello's work. Thanks to Mauricio Vives and Dan Ambrosi for suggestions and testing. Many thanks to all who uploaded photos.
Last change: April 4, 2017