Compute geometric measures

[samgam1981]

HI could you please let me know where to find the source code for the filter-computer geometric measures please,
Need to understand the principles used to calculate the principal axes.

Thanks

[jmespadero]

Hi samgam,

The method that is executed to compute the geometric measures is:

meshlab/src/meshlabplugins/filter_measure/filter_measure.cpp

Line 373 in 3a1d8f2

std::map<std::string, QVariant> FilterMeasurePlugin::computeGeometricMeasures(MeshDocument& md)

Inside that method, there is a call to computePrincipalAxisCloud(const CMeshO& m) which do the work:

meshlab/src/meshlabplugins/filter_measure/filter_measure.cpp

Line 690 in 3a1d8f2

Matrix33m FilterMeasurePlugin::computePrincipalAxisCloud(const CMeshO& m)

Basically

1. Compute in bp the barycenter/centroid of the vertices of the mesh (Average position)
2. Compute in cov the 3x3 matrix of covariances of the coordinates. The actual code of computing the matrix is at https://github.com/cnr-isti-vclab/vcglib/blob/a443e903a66e14a44b170056eee90d233cd753f9/vcg/math/matrix33.h#LL392
3. Return the Eigen Vectors of matrix cov