This is the coordinate system in the OpenGL/Surface window.
Origin: [x, y, z] = 0.5*VMR slice X-resolution, 0.5*VMR slice Y-resolution, 0.5*number of slices
x-axis: anterior to posterior 0 to X-resolution y-axis: superior to inferior 0 to Y-resolution z-axis: right to left 0 to Z-resolution