3DS has grown to become a de facto industry standard for transferring models between 3D programs, or for storing models for 3D resource catalogs.
To export to 3DS, go to File > Export > Export 3DS.
The number of polygons exported determines the overall quality the 3d model will retain when exported to 3DS format. For objects with sharp corners and flat surfaces, this is not terribly important. for smooth or curved objects, (Spheres, NURBS, Sweeps) having more polygons is important.
There are a number of check boxes that allow you to control whether certain types of objects will be exported into the 3DS file or not. If the choice is grayed out, then the exporter has not detected any instances of that particular type of object in the document.
Textures are exported as image files, this is to simplify the re-application of textures to various objects after re-importing the 3DS file into another software. Renderworks handles texturing in Vectorworks products, but since different rendering engines are used in the various 3D modeling packages available, exporting the textures as a simple image is a clean way of allowing 3rd party software to handle textures however it sees fit.
If your model is a single solid object, and has one texture across it or no texturing at all, then it is often wise to select all the separate components of the object and use Model > Add Solids to combine them into one solid figure. this not only reduced complexity when exporting to 3DS, but can also avoid coplanar vertex and surface issues that can arise from exporting multiple separate objects that are intended to be one 3D solid.
Edited by JimW