3DP

// Objekte fürs lineare Gleichungssystem: m*x = b, Lösung kommt in x.
    Mat m, x, b;
    int dim = 3; // the computing dimension (e.g. 3 for X, Y, Z)
    std::stringstream txtDebug;

    // init matrices
    m = Mat(dim*iN, dim+1, CV_64FC1, double(0));
    x = Mat(dim+iN, 1, CV_64FC1, double(0));
    b = Mat(dim*iN, 1, CV_64FC1, double(0));

    // fill matrices with known information
    for (int i=0;i<iN;i++)
        for (int j=0;j<dim;j++)
        {
            m.at<double>(i*dim+j,j)   = 1.0;
            m.at<double>(i*dim+j,dim) = (-1) * matDir.at<double>(j,i);
            b.at<double>(i*dim+j,0)   = matPoint.at<double>(j,i);
        }

    // get inverse of m and solve equation
    x = m.inv(DECOMP_SVD) * b;

    // debug
    for (int i=0;i<x.rows;i++)
    {
        for (int j=0;j<x.cols;j++)
        {
            txtDebug << " " << x.at<double>(i,j) << "; ";   // In die Output Edit Box des Dialogs
            //if (i%4 == 0)
        }
        txtDebug << "\r\n";
    }
    txtOut.Format("%s",txtDebug.str().c_str());