Text and illustrations
© 1998-2008
Brian R. Johnson
except student work
as noted
DATA TRANSFORMATION:
Sweeps
"It had a swoopy sort of shape."
SWEEPS, while conceptually similar to extrusions, involve a (potentially) much more complicated path. A simple sweep, using a simple path, might be indistinguishable from an extrusion, but a sweep such as the form•Z sweep shown at right can be quite complex. The red rectangle is going to be swept along the splined path to form a complex meshed object using Nurbs.
The resulting form is generated by moving the cross-section in steps along the path, each time perpendicular to the local path segment, and connecting it with the polygons already generated.
Variations
As shown in the illustration, the basic framework of the sweep, which might involve a shape as simple as a rectangle, can be used to create quite complex shapes, such as the tube resulting from the sweep shown here.
end-caps
As with most of the "extrusion" operations, swept shapes form a tube which may optionally be "capped" or terminated with a closing polygon (making a solid).Last updated: October, 2001