TouchWandEnv - wand sticks on object

[philtabor]

While the wand is in contact with the object the movement slows down, giving the appearance that the wand is stuck on the object. This is noticeable during the rendering process.

Wand should not show an appreciable slowdown while in contact with the object.

Related to the use of the computeProjectionMatrixFOV and getCameraImage functions. These introduce overhead that causes the time between successive calls to _step, thus giving the appearance of a slowdown.