Exported mesh isn't closed

I’ll get right to it. I am trying to analyse a hull form for a ship and to do this i have found a python library called numpy-stl which is capable of analysing functions on a mesh. For those suggesting i use grasshopper, i don’t want to as i need to use some type of goal seek function or binary search.

However, the python library keeps returning a warning that the mesh in the stl file is not closed. The volume and centroid calculations match those of rhino, but i am worried that later on this issue will start causing issues. How do I ensure the mesh is actually closed. I am fairly certain the solid is a closed polysurface. See some screenshots below.


The first image is to try and show that the polysurface has no naked edges and the second image is the warning numpy-stl library gives.

Hopefully someone can help me out here. Any other suggestions for other libraries or methods are also welcome.

If you create an .stl of your model directly in Rhino then re-import it, is it closed? Does Check say it’s a good mesh?

Moved to Rhino for Windows category.

Hello - are you handing the py script a mesh object, or the polysurface and python getting the meshes from the faces?


If nothing else works, maybe Netfabb can fix your mesh.

When I reimport it, I just get the mesh itself, so all the triangles. Not sure how I make a surface out of it again but it all seems so be in one piece. How do i check if the mesh is good?

I am handing the python script a mesh object. I exported it as a binary stl file so it should be opening a mesh. The py code importing it is …

ship_mesh = mesh.Mesh.from_file('ship_mesh.stl')

Hello - run ShowEdges on the mesh - look for any nakeds.