CompuServe Thread

Pencil Emulation

7 messages in this thread
#113711From: Michael SternbergJul 18, 1990 11:45 PM
Here's an idea that I thunk the other day: In computer graphics, particularly paint programs, one important area has not been addressed. That is, we have no means of varying line thickness as we draw by varying "pen" pressure. I offer this possible approach to anyone who wishes to pursue it (I'll probably regret this): Beneath the standard graphics tablet surface grid, place a piezoelectric film. The film, when subjected to greater pressure, would alter the voltage applied across the film. This change in voltage would be read and software (the paint program) would vary the line thickness proportionately. If standard fixed line width was desired, this feature could be toggled off. Is this idea with any merit?
#113733From: Kevin DarlingJul 19, 1990 2:33 AM
I think either that idea, or the idea of placing a pressure sensor inside the stylus (cheaper – grin), has been done, yah. Real spray brush behavior with varying thicknesses, etc. Good idea, tho!
#113820From: Alex ArthurJul 19, 1990 9:28 PM
Oops! Looks like I spoke too soon (didn't read the rest of my messages before responding to the original message). Anyway, it's not necessary to go through this much effort for a realistic airbrush technique. CGL, Inc. sells Images II, (a painting system) which has this and many other effects, using a normal tablet/stylus. For example, you could randomly distribute pixels at a given radius from stylus. You can even do blending with neighboring pixels. While I'm not a graphics programmer, I know that it has been done. Cheers! Al Alex Arthur – Unix System Programmer – NYIT Computer Graphics Lab 4 McKinley Place, Glen Cove, NY 11542
#113831From: Kevin DarlingJul 19, 1990 10:40 PM
Ayup, that's true! Thanks, Al!
#114527From: Andre PageJul 26, 1990 6:55 AM
How about changing the thickness by mouse speed, fast = thin, Slow =Thick?
#113819From: Alex ArthurJul 19, 1990 9:27 PM
Another way would be to incorporate a stress-gauge within the stylus. Al Alex Arthur – Unix System Programmer – NYIT Computer Graphics Lab 4 McKinley Place, Glen Cove, NY 11542
#113909From: Miles KurlandJul 20, 1990 11:32 PM
Michael, There are some very nice graphics tablets that do currently incorporate pressure sensitivity, such as several models of Numonics, Zed Pens, and my personal favorite, Wacom. The Wacom is especially nice because it uses a wireless stylus that has a nice balance to it – early wireless styli were heavy, this is light. I work for a software company, Time Arts, that produces a paint package called Lumena, which has used this pressure information for over 3 1/2 years, not only using it to vary line thickness, but also density of airbrushes, and stipple for expressive brushwork… it can fairly closely emulate traditional media, and in many ways, be more controllable. So your idea is pretty good!