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@@ -561,17 +561,27 @@ The output UV coordinate system has its origin in the lower-left corner:
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@endcode
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Use the #aiProcess_FlipUVs flag to get UV coordinates with the upper-left corner als origin.
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-All matrices in the library are row-major. That means that the matrices are stored row by row in memory,
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-which is similar to the OpenGL matrix layout. A typical 4x4 matrix including a translational part looks like this:
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+A typical 4x4 matrix including a translational part looks like this:
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@code
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X1 Y1 Z1 T1
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X2 Y2 Z2 T2
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X3 Y3 Z3 T3
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-0 0 0 1
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+ 0 0 0 1
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@endcode
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-with (X1, X2, X3) being the X base vector, (Y1, Y2, Y3) being the Y base vector, (Z1, Z2, Z3)
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-being the Z base vector and (T1, T2, T3) being the translation part. If you want to use these matrices
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-in DirectX functions, you have to transpose them.
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+with <tt>(X1, X2, X3)</tt> being the local X base vector, <tt>(Y1, Y2, Y3)</tt> being the local
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+Y base vector, <tt>(Z1, Z2, Z3)</tt> being the local Z base vector and <tt>(T1, T2, T3)</tt> being the
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+offset of the local origin (the translational part).
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+All matrices in the library use row-major storage order. That means that the matrix elements are
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+stored row-by-row, i.e. they end up like this in memory:
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+<tt>[X1, Y1, Z1, T1, X2, Y2, Z2, T2, X3, Y3, Z3, T3, 0, 0, 0, 1]</tt>.
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+
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+Note that this is neither the OpenGL format nor the DirectX format, because both of them specify the
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+matrix layout such that the translational part occupies three consecutive addresses in memory (so those
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+matrices end with <tt>[..., T1, T2, T3, 1]</tt>), whereas the translation in an Assimp matrix is found at
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+the offsets 3, 7 and 11 (spread across the matrix). You can transpose an Assimp matrix to end up with
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+the format that OpenGL and DirectX mandate. To be very precise: The transposition has nothing
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+to do with a left-handed or right-handed coordinate system but 'converts' between row-major and
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+column-major storage format.
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<hr>
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Kim Kulling