savePLYFile does not save face elements

[VictorLamoine]

When saving a point cloud using savePLYFile; the number of faces (always 0) is not written in the file.

The file is ok to be read by MeshLab etc.. but this missing line prevents loading the file with loadPolygonFilePLY because VTK expects a face 0.

Here is the minimum expected by VTK:

  if ( (elem = vtkPLY::find_element (ply, "vertex")) == NULL ||
       vtkPLY::find_property (elem, "x", &index) == NULL ||
       vtkPLY::find_property (elem, "y", &index) == NULL ||
       vtkPLY::find_property (elem, "z", &index) == NULL ||
       (elem = vtkPLY::find_element (ply, "face")) == NULL ||
       vtkPLY::find_property (elem, "vertex_indices", &index) == NULL )
    {
    vtkErrorMacro(<<"Cannot read geometry");
    vtkPLY::ply_close (ply);
    }

[stale]

Marking this as stale due to 30 days of inactivity. It will be closed in 7 days if no further activity occurs.

[kunaltyagi]

Would merely adding an extra "face 0" line to the PLY writer suffice?

[VictorLamoine]

From what I remember yes!

[mvieth]

Fixed by #4774