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My mesh object is based on a CT bone scan so there are many inner geometries due to natural spaces in human bones. But I need a model that has no inner geometries. How do I fill inner holes and spaces with completely solid mesh?

Thanks

Update: I attached a screenshot of the "holes" in my mesh after boolean op.

enter image description here

booleaned:

original:

enter image description here

enter image description here

John
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    maybe you wish to remove internal geometries and fill (or remove) holes left on the surface? can you share at least an example image of a typical zone? – m.ardito Jun 19 '17 at 08:48
  • I think you need to use the Solidify modifier in modifier panel – Victor Ijishakin Jun 19 '17 at 09:11
  • Related https://blender.stackexchange.com/questions/50252/can-i-fill-this-object/50254#50254 – Duarte Farrajota Ramos Jun 19 '17 at 19:10
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    Also see https://blender.stackexchange.com/questions/43150/removing-internal-geometry-before-3d-printing – Duarte Farrajota Ramos Jun 19 '17 at 19:11
  • Thanks all. I attached a screenshot but could not figure out how to attach .blend file :( – John Jun 19 '17 at 21:08
  • @DuarteFarrajotaRamos Thanks for the links. I read your answer carefully. However I thought my mesh is watertight and manifold (?), it is just unfortunately has a lot of internal geometry. Perhaps another way to articulate my question is "how do I duplicate my object using its exterior geometry only"? Thanks. – John Jun 19 '17 at 21:26
  • You can share a file through http://blend-exchange.giantcowfilms.com If your mesh is watertight already that may make things easier, but anyway this question is frequently asked around here if you search you'll find that there is no easy "one button" solution, other than manual laborious cleanup – Duarte Farrajota Ramos Jun 20 '17 at 16:51
  • Thank you all. I just shared my blender file. I am willing to learn the manual laborious way to clean up if needed. Please give me some pointers. Also I tried solidify modifier. It didn't work exactly the way I want it but I am still reading. – John Jun 20 '17 at 23:30

1 Answers1

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If your geometry has true interior faces

see an older version of the answer:

If there is no disjoint interior geometry.

a manual way..

  • First in edit mode unselect all geometry.
  • use box select (b) to select the visible outer faces, and rotate the model around and add to the selected set by doing more box selects until all outer faces are selected. You can also use the other selection methods, C enters a mode that lets you "paint" selections by leftclicking and dragging the mouse around (esc to exit that mode).
  • Then hit Z to see the model as see-through, you'll notice many unselected verts, those would be considered interior for your purposes.
  • Ctrl+I to invert selection. enter image description here
  • X , delete vertices.

Holes

The problem then would be that the model now has holes that need to be filled.

A strategy to continue this in Blender is to select all edges that only attach to 1 face. You do this by selecting one such edge, and then doing

  • Select -> Select Similar -> Amount of Faces around an Edge.

enter image description here

I don't think you'll get away with hitting F (to Fill) and Ctrl + T to triangulate the result. (as shown below)

enter image description here

There are applications like MeshMixer that can do these tasks automatically, but I say this not as an endorsement - rather as an avenue to explore if you need to do this type of processing a lot. When you relinquish control to a program there's always a trade-off.

zeffii
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    Thanks to yours and Duarte FarrajotaRamos answers, I now understood Blender is not meant to be a CAD tool. I tried to select interior faces as you illustrated. It didn't work. I am including the complete mandible here. If you can help me select interior faces then great! if not, I will have to switch to another software package. – John Jun 23 '17 at 03:39
  • In that file there are no detached interior cavities (unlike swiss cheese) , it's all one intricate surface with holes on the outer surface that lead to interior cavities. I can't think of any automated Blender tools that will make this task any easier (that doesn't mean there aren't any) . I'll update my answer – zeffii Jun 23 '17 at 07:51
  • I think you might be looking for a different tool, MeshMixer springs to mind. – zeffii Jun 23 '17 at 08:13
  • Thanks again. After I applied box select a few times all over the exterior, some how all polygons were ended up selected. So it didn't quite work out. Interesting solution though! – John Jun 25 '17 at 01:18
  • @John, don't do the box selection mode while the viewing mode is transparent or Blender will select everything in sight. There also a button that enables you to pick occluded geometry (beside vert,edge,face selection icons) i bet it was pressed in. – zeffii Jun 25 '17 at 09:05
  • Yes that worked! Now I have a hollow object without any interior geometry. (see pic in original post). Now I just need to figure out how to "fill" inside using maybe meshmixer. Thanks! – John Jun 26 '17 at 06:13
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    Thank you all I think I did it. Appreciate all the help. – John Jul 02 '17 at 01:40