A model is no better than a image without animation. So at the minimum it needs to support animation. But of course an animation with no interactivity is no be

A model is no better than a image without animation. So at the minimum it needs to support animation. But of course an animation with no interactivity is no better than a video. So it needs to support interactivity. Now you're talking about a bunch of scripting, to which (as they point out) Babylon and Three.js are well suited. I don't see the point of adding this to the browser when canvas exists, unless the point is to take components out of Babylon/Three and put them into fast browser code.