> I am using Vortex and ODE. In ODE, rotation is defined in 4x3 matrix. > In Vortex transformation is defined in 4x4 matrix. Is there any direct > mapping between them? The mapping is there, and obvious to anyone who understands linear algebra. The ODE 3x3 matrix is the upper-left 3x3 of a 4x4 transform matrix. Just copy it, and fill in the missing bits. Cheers, / h+