Add an orbit camera mode
The default camera control in the viewer is a trackball style, I prefer orbit controls generally. Something like is shown in this video:
Trackball controls can roll the model which can make it difficult to know which way up it is. Perhaps this can be controlled with a command line switch or a config setting. I'd always want to use orbit controls so I'd need some way of making it default.
There are a similar camera models in Three.js and Babylon.js and most 3D modelling tools.
Edited by orangebowlerhat