Hello, This seems very wrong to me...
I was looking into the inverse of the classes. And I saw how the matrix was composed from the scale and versor components[1] newMatrix[0][0] = m_Scale[0] - 2.0 * ( yy + zz ); newMatrix[1][1] = m_Scale[1] - 2.0 * ( xx + zz ); newMatrix[2][2] = m_Scale[2] - 2.0 * ( xx + yy ); newMatrix[0][1] = 2.0 * ( xy - zw ) + ( m_Skew[0] ); newMatrix[0][2] = 2.0 * ( xz + yw ) + ( m_Skew[1] ); newMatrix[1][0] = 2.0 * ( xy + zw ) + ( m_Skew[2] ); newMatrix[1][2] = 2.0 * ( yz - xw ) + ( m_Skew[3] ); newMatrix[2][0] = 2.0 * ( xz - yw ) + ( m_Skew[4] ); newMatrix[2][1] = 2.0 * ( yz + xw ) + ( m_Skew[5] ); Similarly both classes just add the scale/skew component and don't do correct matrix composition. Let R be the versor, S scale, and K skew matrices, and p be a point. Currently we have: (R+S+K)*p = R*p+S*p+K*p Where I expected these classes would be implementing: R*S*K*p which is a traditional composition of transform matrices. Anyone know where the current math came from? Or what it's really doing? Is this something that we should fix/improve/evaluate? Or just document what's actually happening? Brad [1] https://github.com/InsightSoftwareConsortium/ITK/blob/master/Modules/Core/Transform/include/itkScaleVersor3DTransform.hxx#L219-L227 _______________________________________________ Powered by www.kitware.com Visit other Kitware open-source projects at http://www.kitware.com/opensource/opensource.html Kitware offers ITK Training Courses, for more information visit: http://kitware.com/products/protraining.php Please keep messages on-topic and check the ITK FAQ at: http://www.itk.org/Wiki/ITK_FAQ Follow this link to subscribe/unsubscribe: http://public.kitware.com/mailman/listinfo/insight-developers
