一种基于 ASCII 格式的三维物件描述；定义了组成曲面的平面网格与顶点集合。
To open, import, insert, and attach a file as a worksession
| 1. | From the File menu, click Open or Import. |
| 2. | In the Open dialog box, select the supported file type. |
| 3. | If the import can be configured, click to specify import settings. |
| 4. | Click Open, or press Enter. |
Note: When Rhino opens a non-3dm model, the title bar reflects the name of the model that was opened. When the model is saved for the first time, this model name is entered as the file name.
请参考