About Tessellated Files
You can export solid model information about parts and assemblies in the following formats: STL (Stereolithography Apparatus), RENDER, Inventor, VRML, OptegraVis, Xpatch, MEDUSA, and Wavefront.
STL is used for a variety of purposes, the primary one is rapid prototyping.
The RENDER format creates information used to produce high-quality shaded images of solid models.
The Inventor format creates information that can be read by IRIS Inventor, a 3D graphics toolkit by Silicon Graphics.
MEDUSA exports to an ASCII-based .asc file. The coordinate systems of the models that exist on visible layers are exported to MEDUSA with the tessellated geometry.
Wavefront .obj files represent geometric information in the form of a triangle of models and quilts. Importing parts and assemblies from Wavefront does not create solid geometry. The import of Wavefront .objparts and assemblies creates surfaces.
You can import tessellated files from STL, VRML, DXF, MEDUSA, and Wavefront using > 
Open to create new models or using the > > 
Import command to append part files to existing part models. Use the > 
Assemble > Assemble command to assemble part and assembly models as components of existing assemblies.
Open to create new models or using the > > Import command to append part files to existing part models. Use the > Assemble > Assemble command to assemble part and assembly models as components of existing assemblies.The tessellated files are imported as faceted data. During the import and the append tasks, you can set units for the MEDUSA, STL, and Wavefront models. The units are available as import options on the Misc tab of the import profiles. The units you set persist in the imported models after import.
You can use import and export profiles for the import, append, and export tasks. Import and export log files are automatically generated in the working directory when the import, and export tasks are complete.
File Format
STL and RENDER files represent the surfaces of a solid model as groups of small polygons.
RENDER differs from STL in two respects. RENDER files include:
• The entity color
• A surface normal at each vertex of a polygon element