Hi everybody,

I am using Qwtplot3D 0.2.7 to plot 3D surface and it works fine.

On my own inherited class of SurfacePlot, I also need to plot a 3D polyline.
The only way I found to draw something is to overload the createData() function like this :

Qt Code: 
  1. void PlotSurface::createData()
  2. {
  3.     Qwt3D::SurfacePlot::createData();
  4.     if(!ptrIsNul(_myData))
  5.     {
  6.         Qwt3D::setDeviceLineWidth( 2 );
  7.         glColor3d(0., 1., 1.);
  8.  
  9.  
  10.          glPushMatrix();
  11.          glScaled(_scaleX,_scaleY,_scaleZ);
  12.          glTranslated(_offsetX,_offsetY, _offsetZ);
  13.          glRotated(_angleZ,0.0,0.0,1.0);
  14.  
  15.         glBegin( GL_LINES );
  16.  
  17.  
  18.  
  19.         for(unsigned int i = 0; i < _myData->getNbLines(); i ++)
  20.         {
  21.             for(unsigned int j =0; j < _myData->getLine(i)->getNbPoints()-1; j++ )
  22.             {
  23.                 Point<float,3> p1 = _myData->getLine(i)->getPoint(j);
  24.                 Point<float,3> p2 = _myData->getLine(i)->getPoint(j+1);
  25.                 glVertex3d(p1[0], p1[1], p1[2]);
  26.                 glVertex3d(p2[0], p2[1], p2[2]);
  27.             }
  28.         }
  29.  
  30.         glEnd();
  31.         glPopMatrix();
  32.  
  33.     }
  34. }
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1) Is it the good way to do it ?

2) The lines are drawn. However, when I look the surface plot from above (I then see a X,Y plane), the lines are not at the correct coordinates. Moreover these coordinates depends on the Z values of my surface data. The _offsetX etc... parameters are set to 0 ans _scaleX etc... are set to 1.0. _angleZ is also equal to 0.0.
I would like to draw those lines like the grid of the surface is drawn but I can't find a way.

Any Idea ?

Thanks in advance.