How to prevent integrity loss when making a shape solid?

[Anonymous]

I am attempting to prep a form to send to my 3d printer.  The OBJ file is one I pulled off the internet, and when I try to print it as is, I get errors.  In the past, when I encounter this situation, making the object solid in MeshMixer, then exporting it to STL usually solves the issues.  The problem this time is that when I attempt to make the object solid I lose all sort of integrity in the design; all the edges become soft, plane surfaces become distorted, and structures appear out of nowhere.  See before and after images below:

Can someone explain what's happening, and how I can resolve the issue while maintaining the quality of the initial image?

Thanks.

[hfcandrew]

This tends to happen with severally broken non-manifold models.

MM might be able to do it. But there are many conditions of the mesh to satisfy before each tool will work. Every project and every mesh is a unique snowflake. Maybe your mesh density is too low or too high, or non-manifold, or normals are flipped or they are separated shells. I can't give too much insight and diagnose the problem without the .stl, or at least a screencast or screentogif.

Also read the stickied post regarding soft edges, its just a graphics issue of the default MM shader.