Some Drake University students and I have been working on wrapping the three.js library for 3d webgl graphics and are nearly complete [0]. We also implemented a simple webcam widget [1]. Here's a live demo illustrating both, using the Sage Cell Server: http://sagecell.sagemath.org/?q=qjjurl (you may need to click Evaluate once, and you'll need to click the permission notification to allow the browser to use your webcam)