convert 3d faces from .stl file to solid?

[JamesMaeding]

So I found vb.net code for reading a binary stl, and used that to make my own "import stl to 3d faces" command (in C#).

An stl file is just a text file of triangle verticies, poular with 3d printers and easily available from thingiverse.com.

It occurred to me that I might like to modify the part, then re-export as stl.

Is there a way to "fill" the watertight 3d faces to make a solid?

I thought of converting to region, then to mesh, then to solid, but that did odd things, I think related to surface normals maybe.

This does not have to be an autocad based task. Maybe these are tools in 3dsmax or a solids library out there for this.

I do want the result to eventually be an acad 3d solid though.

thanks

[Balaji_Ram]

Hi James,

Here are two blog posts on creating a solid from a collection of surfaces, but yes the solid creation can fail based on the surfaces and if they overlap or have gaps. 

Collection of surfaces to a solid

http://adndevblog.typepad.com/autocad/2012/03/creating-a-solid-from-a-set-of-water-tight-surfaces.ht...

Mesh to a solid

http://adndevblog.typepad.com/autocad/2014/12/creating-a-solid-from-a-set-of-subdmesh.html

In that case, the other way could be to try and import the STL in Inventor and export the mesh as a DWG.

The mesh can then be converted to a solid.

http://knowledge.autodesk.com/support/inventor-products/troubleshooting/caas/sfdcarticles/sfdcarticl...

I have also seen a plugin for AutoCAD in the Autodesk Exchange Store called the "Polyhedral Mesh To Solid", which you can try.

But please note that I haven't tried it yet.

Regards,

Balaji