Rotate 3D objects or the camera as if touching a trackball.
A three.js control to rotate Object3Ds as if touching a trackball. The point clicked on by the mouse stays under the moving mouse. Touch and momentum support.
Wrote it to help me understand 3D rotations.
After implementing SpinControls.js, I ran across this excellent discussion of 3D rotation approaches here: https://www.mattkeeter.com/projects/rotation/