From cdshaw@umbilicus.artsci.washington.edu Tue Jul 14 21:48:09 1998 Received: from burdell.cc.gatech.edu (root@burdell.cc.gatech.edu [130.207.3.207]) by lennon.cc.gatech.edu (8.8.4/8.6.9) with ESMTP id VAA20509 for ; Tue, 14 Jul 1998 21:48:07 -0400 (EDT) Received: from wheaten.hitl.washington.edu (8uMJ+ghGbVeQbezk5TGymSrZaaxsVmkp@[128.95.73.60]) by burdell.cc.gatech.edu (8.8.4/8.6.9) with ESMTP id VAA22706 for ; Tue, 14 Jul 1998 21:48:06 -0400 (EDT) Received: from umbilicus.artsci.washington.edu (umbilicus.artsci.washington.edu [128.95.248.206]) by wheaten.hitl.washington.edu (8.8.8/8.6.12) with SMTP id SAA32183 for <3d-ui@hitl.washington.edu>; Tue, 14 Jul 1998 18:46:32 -0700 (PDT) Received: (from cdshaw@localhost) by umbilicus.artsci.washington.edu (950413.SGI.8.6.12/8.6.10) id SAA21457; Tue, 14 Jul 1998 18:45:49 -0700 From: Chris Shaw Message-Id: <199807150145.SAA21457@umbilicus.artsci.washington.edu> Subject: 2 hands To: ernst.kruijff@archit.uni-weimar.de Date: Tue, 14 Jul 1998 18:45:49 -0700 (PDT) Cc: 3d-ui@hitl.washington.edu (3D UI List) In-Reply-To: <5F68209F7E4BD111A5F500805FFE35B905797843@red-msg-54.dns.microsoft.com> from "Ken Hinckley" at Jul 14, 98 12:04:56 pm Reply-To: cdshaw@cs.URegina.ca X-Mailer: ELM [version 2.4 PL25] MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Status: RO Hi, > I think Chris Shaw is the best guy to talk to about the modelling > application, as he's done quite a bit of work in this area. Thanks Ken! I have some software you might like to use. It's called the TwoHand library. It runs on top of the MR Toolkit on SGI/OpenGL boxes. THRED: I use a pair of Polhemus sensors with three buttons glued on each. In THRED, I use the left hand to set context and the right for picking and fine manipulation. There is a left cursor and a right cursor. Left operations: Grabbing the object and repositioning/orienting it Menu selection Controlling constrained reshaping Right operations: Pick vertices Drag selected vertices (position change only) Drag selected vertices (position and orientation) The only explicit two-handed technique in THRED is constrained manipulation. The left hand uses one of the buttons to toggle which of the 3 constraint modes there are (Line, Plane, None). Line constraints means that when you grab vertices, they translate parallel to one of the 3 canonical axes. Plane constraints means that grabbed vertices translate in the chosen constraint plane. No constraints means that grabbed vertices move freely in 3D. To choose which axis, you ORIENT the left cursor to align it with the axis you want. (The left cursor becomes a thick line so that it's obvious visually how to align). The left cursor moves freely, while the right cursor has a thick line that snaps to the chosen axis. When you press the Right Drag Selected Vertices button, THRED uses the current snap axis as the axis to move the vertices along. My user tests indicate that people like this technique. The biggest problem to deal with is how to manage button real estate. You only have 6 buttons. This means that you need menus to set modes of various kinds. My menu design is OK, but it could stand improvement. People don't like it as much as regular pull-down menus. See http://www.cs.uregina.ca/~cdshaw/papers/multimedia97.ps.gz for a paper on this editor. -- Chris Shaw University of Regina cdshaw@cs.URegina.ca Assistant Professor http://www.cs.uregina.ca/~cdshaw