The Matrix Details
The ODE library uses a 3x3 matrix in mathematical notation, i.e. row first, column second. However, internally ODE stores
its matrices as a 4x4 ordered matrix, padded with 0's. The good news is that the dBodyGetRotation function we used to
retrieve the rotation matrix in DrawGeom above returns a 4x3 rotation matrix. So the ODEtoOGL function transposes the
elements over to the OpenGL order (column first, row second) and plugs in the position vector into the 12th, 13th and
14th elements.