SpinControls for Three.js
A three.js control to rotate Object3Ds and Cameras as if touching a trackball. Wrote it to help me understand 3D rotations. A little movement momentum after lifting the pointer brings juiciness.
On a touchscreen, 2 fingers roll + pan + zoom the camera like Google maps.
After implementing SpinControls.js, I ran across this excellent discussion of 3D rotation approaches.