How can I set the camera angle to something like the isometric projection?
you need to use orbit and track controls , like in here :
http://codepen.io/nireno/pen/cAoGI
Edit:
also you may consider using ortho camera this post here may help you :
Three.js - Orthographic camera
an example can be seen here :
http://threejs.org/examples/canvas_camera_orthographic.html
and here is a link (udacity) explaining the use:
https://www.udacity.com/course/viewer#!/c-cs291/l-158750187/m-169414761