Merging vtkpolydata and vtkpolydata issue / Add vtkpolydata to vtkpolydata failed / vtkBooleanOperation failed resulting in non-manifold

[hye00525 (Rimu)]

Hello,
I am trying to add cone-shaped or triangular pyramid-shaped vtkpolydata fins to vtkpolydata at specific positions in polydata. (like picture below )

I plan to print this stl using 3d print, and I have tried the vtkBooleanfilter, but failed to print due to the non-manifold issue, so I am asking if there is another good method.

My trials-----

• Merging two vtkpolydata using vtkAppendfilter → 3d print was not possible (It looks like it’s merged, but is impossible to print because the vertex and face are configured separately)

• Merging two vtkpolydata using vtkBooleanfilter: 3d print impossible due to non-manifold creation (same issue as [this person](https://discourse.vtk.org/t/the-result-of-boolean-operation-returns-non-manifold-surfaces /4018) )

• Using Ronald Romer’s vtkbool library: Since my project uses vtk-9, it was difficult to build and use. (Note https://github.com/zippy84/vtkbool/pull/37)

Has anyone tried a similar approach?
Any advice or code example would be great. Thank you.

[lassoan (Andras Lasso)]

We have updated vtkbool to work with latest VTK master and fixed up its Python wrapping. It works very nicely, both in C++ and Python. It can deal with fairly complex meshes for creating 3D-printable surgical guides:

The modified vtkbool code is available here. We have not pushed our changes back to upstream because we are waiting for @jcfr’s VTK remote infrastructure to be ready. Until it is ready, you can use vtkbool in Slicer’s GUI, or in the virtual Python environment that Slicer provides, or in C++ Slicer modules, or (as a short-term workaround) just copy the files from our repository and use it in your C++ project.

At some point there was also a vtkbool Paraview plugin, but I don’t know if that is still available.

[hye00525 (Rimu)]

Thank you very much for your detailed explanation and code.
I’ll try it. Have a nice day!