You can import several non-Autodesk 3D Models using the IMPORT command
They are:
For information about IGES files, see "About Importing and Exporting IGES Files."
All imported geometry is created on layer 0. The original colors for all 2D and 3D wire geometry are preserved. They do not acquire the color from layer 0 (color is not ByLayer).
IMPORT maps parts and assemblies to blocks and block references. Individual parts are mapped to blocks, which in turn are referenced from model space. Assemblies are formed by nesting "part" blocks. The name of the block is the same as the name of the corresponding part or assembly in the source 3D model. If a part or assembly name contains unsupported characters, in the corresponding block they are replaced by the underscore (_) character. If a part or assembly name is longer than the maximum block name length, the name is truncated. If this results in identically named blocks, a unique name is assigned to one of the blocks by appending the dollar character ($) to its name, along with a unique number. The original name is preserved in the block description.
The INSUNITS property on the block corresponding to the top level assembly is set to match the source file’s linear units. If the source file’s units cannot be found or is not supported by INSUNITS, the property is set to “No Units”.
Depending on how complex the source file is, the import process can take several minutes, and hence, runs as a background process. Once the background process starts, the Import status bar icon displays. If you hover over the Import status bar icon, a tooltip displays the current status.
Once processing is complete, a notification bubble is displayed on the import status bar icon. If you click the link in the notification bubble, the imported content is inserted in the current drawing. If you close the notification bubble before you insert the imported content, you can insert it later by right-clicking the import status bar icon and choosing "Insert" from the menu.