Vectorworks 2009's Parasolids technology does not allow for self-intersecting solids to be created. This is because in reality, solid matter may not exist in the same location in space as other solid matter. While this is excellent to keep objects as real as possible and make volumetric data more accurate, it requires that the user understand this concept in order to both avoid and work around incorrect practices when drafting.
Importing from previous versions
When a previous version Vectorworks file is opened in Vectorworks 2009, the geometry of the drawing objects is automatically converted using the new kernel. The conversion may fail for some solids for a variety of reasons: for example, if an object has self-intersecting profiles inside an extrude or sweep, or if an object’s surfaces do not pass the Parasolid checks. If this happens, Vectorworks converts all of the other objects and alerts you that some objects were not converted. A wireframe representation of the failed solid is included in the file; you may be able to edit these objects and regenerate the solids.
Extrude Along Path
The path objects for Extrudes along a path may not intersect at any point. Additionally, as the profile object is extruded along the path, it may not come into contact with itself. This is done because in real space, portions of a solid object cannot occupy the same space that other portions of said object already occupy.
Note that even though the objects cannot be created as a single extrude, they can easily be accomplished by separating the patch object, and using the same profile object twice in two separate operations.
Sweeps by default use their leftmost bounds as their spin axis when Swept at a positive angle. The standard way of controlling a sweeps axis is by selecting bot the sweet profile object AND a 2d locus. The locus acts as the pivot point for the sweep. Much like with Extrusions, Sweeps are solid objects and therefore in a Parasolids environment cannot have any two portions of their geometry occupying the same space at the same time.
Note: Sweeps created with a 2D locus "Axis" point within the x-bounds of the profile object in Vectorworks 2008 documents will not appear when the documents are converted to 2009, due to the fact that they create a self-intersecting solid. The pivot point may reside ON the leftmost or rightmost bounds but not WITHIN the leftmost or rightmost boundary of the profile object. To work with this behavior, users should create the desired profile as one half of the desired sweep cross section.
Edited by JimW