The implementation is simple 3D vector scaling and addition. The
HmdMatrix34_t consists of a 3x3 rotation matrix and a 3D vector for
position.
The overlay position is only updated whenever a new overlay is changed
because we need the old overlay position in order to modify it. The
openvr call to get the position is only updated whenever you open the
menu.
A new page was created due to lack of space on the utilities page.
Vasily