# Right handed system to left

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EverIce    151
Hi ! I've exported a mesh from max 5.1 to direct3d. Max has right handed system. My question how to transform vertices and local trans matrices to left handed system ? I'd be glad for any help.

greldik    163

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EverIce    151

Have i got to transpose matrices ? Switch column and line ?

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greldik    163
If you use column-vectors and 3dsmax use row-vectors, or the other way around, then you have to transpose the matrices you get from 3dsmax.

Remember

if you use row-vectors:
           [a, b, c [1, 1, 1]   d, e, f  ==  [a+d+g, b+e+h, c+f+i]            g, h, i]

and for column-vectors:
[a, b, c    [1 d, e, f  *  1   ==  [a+b+c, d+e+f, g+h+i] g, h, i]    1]

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EverIce    151
Thanks for the help.

Max Matrix3 is an 4*3 matrix. It seems to be a column matrix. Are you sure i have to transpose ?

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greldik    163
4x3 probably means that you have the position in the last row, correct? In that case, it is a row matrix.
And if you use the same type of matrices you don't have to transpose them