Date: Fri, 23 Nov 2001 16:17:00 -0500 From: "Jeff Pierce" Subject: Re: 2D interfaces in a 3D environment In-reply-to: <3BFDC956.92ADF0F1@cs.yorku.ca> Sender: X-Sender: jpierce@ux2.sp.cs.cmu.edu To: "3D UI list" <3d-ui@hitl.washington.edu> Message-id: <4.1.20011123160501.00a4de00@ux2.sp.cs.cmu.edu> MIME-version: 1.0 X-Mailer: QUALCOMM Windows Eudora Pro Version 4.1 Content-type: text/plain; charset=iso-8859-1 Content-transfer-encoding: 7BIT Importance: Normal X-MSMail-Priority: Normal X-MimeOLE: Produced By Microsoft MimeOLE V4.72.3110.3 References: <3BF9D3A2.5E8EA9C@home.com> <4.1.20011121135214.00bc4100@ux2.sp.cs.cmu.edu> X-Authentication-warning: torch.hitl.washington.edu: majordom set sender toowner-3dui@hitl.washington.edu using -f X-Priority: 3 (Normal) At 10:58 PM 11/22/01, Wolfgang Stuerzlinger wrote: >Jeff Pierce wrote: >> >> At 09:12 AM 11/21/01, Wolfgang Stuerzlinger wrote: >> >Taking this argument one step further one can use what most people percieve >> >as normal or "common sense" (e.g. that gravity exists :-) and use this to >> >simplify interactions even further. This improves interaction speed by >> >a factor of approximately 2.5. See the papers on the MIVE system >> >on my WWW page. >> >> Improves interaction speed for what task? There are some obvious examples >> (manipulation of objects at a distance, navigating large distances) where >> using what people perceive as normal (or, more accurately, familiar) is >> much, much slower than using a "magic" technique. > >True. However, I would like to point out that even "magic" techniques >can benefit from "common sense". Take e.g. a 6 DOF tracker, where >the tracker position & orientation are used to do ray-casting for one >of many interaction-at-a-distance techniques. Users expect e.g. >a distant house to stay flat on the ground when it is moved around, >yet the 6DOF tracker makes this practically impossible, due to rotation >around the ray axis. "Common sense", be it implemented as gravity or >as an "on-floor" constraint, will make a lot of difference even in >this case. I wouldn't label what you're taking advantage of common sense. In the real world common sense tells me that I can't move a house, not that it should stay flat on the ground when I move it around. In addition, objects in the real world don't stick to surfaces. You're actually doing a different type of helpful magic: the system constrains the motion of objects in a non-real world manner in order to simply my manipulation of them. >> And as a minor point, I can posit virtual worlds where you _don't_ want >> gravity. Why on earth would I want things to fall to the floor if I >> accidentally drop them? It'd be much easier if they hovered within reach >> so that I could grab them again. > >I care to disagree. My experience with taking people "off-the-street" >into VR environments is that they don't like objects floating in the air >in essentially arbitrary positions & orientations. One issue here is >that floating objects often block the view of other objects, which >hinders people. Another is that the orientation of the object makes it >often inconvenient to further manipulate the object. More importantly, >people working in zero-g (astronauts) don't leave things floating in >space, even though they could theoretically. They attach objects as much >as possible onto surfaces or other objects to keep things surveyable and >to maximize space for moving around. They don't like it because it's inconvenient, or they don't like it because it's not "common sense"? Certainly there are situations where objects that float around you are inconvenient, just as there are situations where objects that fall to the ground are inconvenient. >But yes, I do agree that it sounds good to just "hang something into >the air" and there are some interesting uses of this (e.g. Mark Mine's >over-the-shoulder delete/recover idea). I just think that floating >objects is a bad choice for the system-wide default in VR systems/toolkits. I think we're in agreement here, we're just approaching the issue from different sides. Certainly there are situations where emulating the real world is convenient, just as there are situations where emulating the real world is inconvenient. The same argument applies for "magic" techniques: sometimes they help, sometimes they hinder. I certainly would not make the argument that "magic" behavior (e.g. floating objects) should always be the default in VR systems or toolkits. But I wouldn't make the argument that real world behaviors should be the default either. The key will be to figure out what the right blend is of magic and real world behavior. Incidentally, people do _not_ always expect real world behavior in VR. In the work I did with Disney Imagineering on the DisneyQuest project one of the lessons I learned is that you can shape people's expectations in virtual env