Is it possible to rotate a control in a circular direction? Like hands on a clock or a gear by using your finger on the iPhone/iPad? I also need to control the speed, so the faster you spin the controller the faster the object moves.
It is definitely possible but a little complicated.
In the example of a clock,
1- you create a raycast of the finger input positions (which are bidimensional) on the 3d scene, and determine where the finger is pointing in the 3d world (in respect to the camera)
2- you use the 'raycast.hit' coordinates of point 1's projection to set the transform.position of an empty gameobject that you use as focus
3- you update the arm clock's rotation by subtracting the focus' position to its own and determining the rotation angle
There’s quite a bit of coding involved, but the guidelines are those you need to follow for the fastest solution I believe.