This is one of those updated features in AutoCAD 2012 that people may not be aware of. You can import several non-Autodesk 3D formats into AutoCAD 2012 including .3DM files from Rhino.
Command line: IMPORT
Ribbon: Insert tab > Import panel > Import
Menu: File > Import
Here are the formats the IMPORT command will import:
- 3D Studio (*.3ds): 3D Studio files
- ACIS (*.sat): ACIS solid object files
- CATIA V4 (*.model; *.session; *.exp; *.dlv3): CATIA® V4 model, session and export files
- CATIA V5 (*.CATPart; *.CATProduct): CATIA® V5 part and assembly files
- FBX files (*.fbx): Autodesk® FBX files
- IGES (*.igs; *.iges): IGES files
- JT (*.jt): JT files
- Metafile (*.wmf): Microsoft Windows® Metafile
- MicroStation DGN (*.dgn): MicroStation DGN files
- Parasolid binary (*.x_b): Parasolid binary files
- Parasolid text (*.x_t): Parasolid text files
- Pro/ENGINEER (*.prt*; *.asm*): Pro/ENGINEER® part and assembly files
- Pro/ENGINEER Granite (*.g): granite files generated by Pro/ENGINEER
- Pro/ENGINEER Neutral (*.neu): granite neutral files generated by Pro/ENGINEER
- Rhino (*.3dm): Rhinoceros® model files
- SolidWorks (*.prt; *.sldprt; *.asm; *.sldasm): SolidWorks® part and assembly files
- STEP (*.ste; *.stp; *.step): STEP files