Path: utzoo!utgpu!water!watmath!clyde!att!rutgers!cmcl2!nrl-cmf!ames!pasteur!ucbvax!decwrl!labrea!hanauma!rick
From: rick@hanauma (Richard Ottolini)
Newsgroups: comp.sys.mac.programmer
Subject: Re: 3-D rotation
Message-ID: <23327@labrea.Stanford.EDU>
Date: 19 Aug 88 15:40:43 GMT
Sender: news@labrea.Stanford.EDU
Reply-To: rick@hanauma (Richard Ottolini)
Organization: Stanford University, Dept. of Geophysics
Lines: 13


There was a nice study of the user interface problem in the 1988 SIGGRAPH
proceedings (Computer Graphics, v.22, n.4, p.121) by Chen et al.
"A Study in Interactive 3-D Rotation Using 2-D Control Devices.
They studied four types of controlers:
(1) separate x,y,z sliders (e.g. scroll-bars)
(2) overlapping sliders: rendered as a 9-square. The interior cross controls
x and y.  The corners control z.
(3) continuous xy + z: one mouse state gives continous xy rotation and 
another controls z.
(4) virtual sphere (trackball): rendered as a circle.
As generally expected #1 and #2 make axial rotations easier while #3 and #4
make non-axial rotations easier.  (I'd put one of each in my application then.)