.3DM file extension

This is the basic program to work with .3DM extension

Rhinoceros Rhino 3-D Model

Rhinoceros is a powerful program that allows you to create complex models. It provides enhanced commands such as direct sub‑object manipulation and thin‑wall shelling, it provides support for texture mapping, 3D rendering, post-rendering effects and it also allows you to analyze your 3‑D models... (more)

The program works with the following extensions: 3dx, rhp, 3dm and rws

.3DM extension is also supported by the following programs:

Mesh To Solid Mesh Document

Mesh To Solid - Software to convert a mesh to a solid.

Deep Exploration Deep Exploration 5.5 Quicktime 3D Metafile

Deep Exploration - a manipulation tool for 2D and 3D product graphics.