larry@csccat.cs.com (Larry Spence) (03/28/91)
Some readers may be familiar with a CAD/drawing product from Ashlar named
Vellum. One of its main features is its so-called Drafting Assistant.
While drawing or editing in Vellum, as the cursor is moved, the program
dynamically detects proximity to intersections of other lines and curves,
midpoints of primitives, and other "likely" snap points. The advantage is,
of course, that the user need not explicitly request the snaps, they are
determined on-the-fly and the user is notified (via a status line) what
"key" point or line he/she is near.
As I was reading through some Ashlar promotional material, I noticed that
the Drafting Assistant is "patent pending." I can't see how this could
be granted, given that the SIGGRAPH 1986 paper
Snap Dragging
E.A. Bier (EECS, UC Berkeley) & M.C. Stone (Xerox PARC)
SIGGRAPH 1986 Proceedings
pp. 233-240
desribes a system implemented at PARC which appears to be a superset of
the Assistant. The authors' scheme of "alignment objects" is _very_ similar
to Vellum's, right down to visible "guidelines" in a distinguished color.
Any and all info (patent #) and comments would be appreciated. Thanx.
--
Larry Spence
larry@csccat.cs.com
...{uunet,texsun,cs.utexas.edu,decwrl}!csccat!larryuselton@nas.nasa.gov (Samuel P. Uselton) (03/29/91)
In article <4213@csccat.cs.com> larry@csccat.cs.com (Larry Spence) writes: >Some readers may be familiar with a CAD/drawing product from Ashlar named >Vellum. One of its main features is its so-called Drafting Assistant. >While drawing or editing in Vellum, as the cursor is moved, the program >dynamically detects proximity to intersections of other lines and curves, >midpoints of primitives, and other "likely" snap points. The advantage is, >of course, that the user need not explicitly request the snaps, they are >determined on-the-fly and the user is notified (via a status line) what >"key" point or line he/she is near. > >As I was reading through some Ashlar promotional material, I noticed that >the Drafting Assistant is "patent pending." I can't see how this could >be granted, given that the SIGGRAPH 1986 paper > > Snap Dragging > E.A. Bier (EECS, UC Berkeley) & M.C. Stone (Xerox PARC) > SIGGRAPH 1986 Proceedings > pp. 233-240 > >desribes a system implemented at PARC which appears to be a superset of >the Assistant. The authors' scheme of "alignment objects" is _very_ similar >to Vellum's, right down to visible "guidelines" in a distinguished color. > >Any and all info (patent #) and comments would be appreciated. Thanx. > >-- >Larry Spence >larry@csccat.cs.com >...{uunet,texsun,cs.utexas.edu,decwrl}!csccat!larry Speaking of "prior art".... Didn't Ivan Sutherland's Sketchpad system (circa 1962!!) have some alignment, touching, parallel and such constraints? I'm remembering a demo I saw on video, taken from an early network TV science program. Any patent on such things must be on the particular method of implementation, not on the idea of the computer enforcing constraints. The first edition of Newman & Sproull (1973?) also discussed gravity fields around "likely" snap points as an implementation method. Sam Uselton uselton@nas.nasa.gov employed by CSC working for NASA speaking for myself