Processing Forum
// By default, the camera is in "free rotation" mode, but you can // constrain it to any axis, around the look-at point: camera.setYawRotationMode(); // like spinning a globe camera.setPitchRotationMode(); // like a somersault camera.setRollRotationMode(); // like a radio knob camera.setSuppressRollRotationMode(); // Permit pitch/yaw only. // Then you can set it back to its default mode: camera.setFreeRotationMode();