From drewk@graphics.cis.upenn.edu Thu Jun 18 10:30:36 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 KAA15571 for ; Thu, 18 Jun 1998 10:30:34 -0400 (EDT) Received: from wheaten.hitl.washington.edu (7RN5FgHayp8yGtlrcM8lkUQUSuRUcHmB@[128.95.73.60]) by burdell.cc.gatech.edu (8.8.4/8.6.9) with ESMTP id KAA14367 for ; Thu, 18 Jun 1998 10:30:33 -0400 (EDT) Received: from linc.cis.upenn.edu (LINC.CIS.UPENN.EDU [158.130.12.3]) by wheaten.hitl.washington.edu (8.8.8/8.6.12) with ESMTP id HAA13507 for <3d-ui@hitl.washington.edu>; Thu, 18 Jun 1998 07:30:18 -0700 (PDT) Received: from graphics.cis.upenn.edu (GRAPHICS.CIS.UPENN.EDU [158.130.2.10]) by linc.cis.upenn.edu (8.8.5/8.8.5) with ESMTP id KAA16383; Thu, 18 Jun 1998 10:30:16 -0400 (EDT) Received: from roger.cis.upenn.edu (ROGER.CIS.UPENN.EDU [158.130.12.70]) by graphics.cis.upenn.edu (8.8.5/8.8.5) with SMTP id KAA24297; Thu, 18 Jun 1998 10:30:16 -0400 (EDT) Received: by roger.cis.upenn.edu id OAA17306; Thu, 18 Jun 1998 14:30:15 GMT Date: Thu, 18 Jun 1998 14:30:15 GMT Posted-Date: Thu, 18 Jun 1998 14:30:15 GMT Message-Id: <199806181430.OAA17306@roger.cis.upenn.edu> From: Drew Kessler MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: Ken Hinckley Cc: 3D UI list <3d-ui@hitl.washington.edu> Subject: RE: input devices In-Reply-To: <5F68209F7E4BD111A5F500805FFE35B9057977D2@red-msg-54.dns.microsoft.com> References: <5F68209F7E4BD111A5F500805FFE35B9057977D2@red-msg-54.dns.microsoft.com> X-Mailer: VM 6.22 under 19.15 XEmacs Lucid Status: RO Ken Hinckley writes: > I think the other point that Chris made, that the hand-held devices allow > greater precision of manipulation, is the more important issue. Even if you > actually strap the tracker to your finger, gloves provide only very coarse > manipulation compared to an object you can tumble in your fingers. You know, I like props. They make the job of the software much easier, and provide that reassuring haptic feedback. But I would like to point out that one of the touted benefits of 3D environments is that it replaces any physical mock-up prop with a single prop: the computer display. In this spirit, I would argue that a input device tool is not as general as an accurate model of the user's motions. In particular, it seems to me that an accurate model of a user's hand motions would record manipulations as precise as would a prop being manipulated by the hand (minus the extremely fine motions due to the finger surface deformations). Granted, it is much harder from the software point of view to translate finger motions to an object motion. A question to be asked, here, is: can a hand input device be created which provides sufficient accuracy for recording fine motions. My experience with the CyberGlove (6 years ago) is that it wasn't very accurate in reporting the current angle of the finger joints, but the reported angles were not noisy and were fairly accurate in reporting angle changes (especially when the fingers weren't bent too much, which is the case for fine finger manipulations). Therefore, I'm not sure I would agree with a statement that "gloves provide only very coarse manipulation compared to an object you can tumble in your fingers." > The other key issue, which I don't think anyone mentioned yet, is that with > a glove you absolutely need a clutching mechanism if you want to orient > objects in any direction. With a hand-held tracker or prop, then a clutch > isn't necessary (but may be desirable depending on the precise task > constraints) -- so as a designer you have another option that I feel you > don't have with gloves. I don't understand what is so hard about clutching using a hand input device. Could I not simply press my fingers together to grab, rotate (move fingers and thumb in opposite directions, or twist wrist), open my fingers to release, grab, etc? Of course, the software should support this technique, and not change the axis/origin of rotation while it perceives a single object rotation actions. I can think of a lot of physical objects that require clutching (most bigger than my hand). Also, I cannot rotate a small physical object smoothly over one rotation in any direction without pausing, unless I use two hands. Could I not do this with two, accurate hand input devices? What am I missing here? To summarize: Props make good input devices when matched to the task at hand, and are relatively easy to use by software. However, they do not provide a general solution to user input (what if I want to manipulate objects of very different sizes, but don't want to buy a tracker for each?). Hand input devices (eg. gloves) provide a model of the user's hand, which if accurate enough, I believe could be the general solution. My point: gloves may suck now, but I don't think they will suck in 5-10 years. -Drew -- ___________________________________________________________________________ G. Drew Kessler drewk@central.cis.upenn.edu Dept. of Computer and Information Science Office: 174 Moore Bldg University of Pennsylvania Phone: (215)573-2815 200 South 33rd Street Fax: (215)898-0587 Philadelphia, PA, USA 19104-6389 http://www.cis.upenn.edu/~drewk/home.html