The matrices used to describe model transformations are affine 4x4 matrices which are D3D style, row major with translations in the 4th row. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 The translation vector Tx,Ty,Tz is in elements 13,14,15 If you use the transposed scheme, which is: 1 5 9 13 2 6 10 14 3 7 11 15 4 8 12 16 With the translation vector in elements 13,14,15 you can use this matrix without any conversion. It is also important to note that the transformations should include no scaling, as it disrupts the consistency of the collision model.