Path: utzoo!utgpu!news-server.csri.toronto.edu!rutgers!usc!zaphod.mps.ohio-state.edu!uakari.primate.wisc.edu!dali.cs.montana.edu!ogicse!milton!wex@dali.pws.bull.com From: wex@dali.pws.bull.com (Buckaroo Banzai) Newsgroups: sci.virtual-worlds Subject: Re: "Space" -- electron energies Message-ID: Date: 17 Aug 90 22:58:42 GMT References: <9007250107.AA01311@hitl.vrnet.washington.edu> Sender: hlab@milton.u.washington.edu Organization: Bull Worldwide Information Systems Inc. Lines: 44 Approved: hitl@hardy.u.washington.edu [I said:] In particular, it allows you to construct displays where one dimension represents a measured property and another dimension does not. [Bruce Cohen replied:] Is this really what you mean to say? I thought the definition of a dimension included some notion of measurement, whether it's continuous or not is another story. Yes, that's really what I meant. Remember that our data comes from the "real world" even if it is somewhat abstract. The real world can be very recalcitrant. The desired property may simply never exist on the object in question, or it may exist but not be recorded in the system, or it may have become corrupted, or the person viewing is not authorized to see it, or... Of course the property must be, in theory, measurable, but that doesn't say much. It's hard if your display space is of topological dimension larger than 3, but then most *everything* is hard to display. As I mentioned in a previous article, humans seemed to have evolved in 3D space, and have trouble visualizing higher spaces. True, true. That's why you do a lot of selecting out of groups of dimensions. It's also why you have to go to automatic icons fairly quickly. There are two choices: the kludgier one is to pick a plane transverse to the third axis to put the 2D object in, that is, identify ill-defined positions with a unique position. The cleaner way is simply to place all the 2D objects in a plane transverse to the 3D axis, and then extrude them parallel to it. Having done that, it's easy to see where the true 3D objects intersect with the extrusions. What about a 1D object? (I also don't see why one method is "kludgier" than another. Yours, it would seem, would obscure a lot more of the display. Also, if you're trying to convey additional information with the objects (auto-icons again), extrusion may cause things to mean more than they ought. Shapes are important, too :-) -- --Alan Wexelblat phone: (508)294-7485 Bull Worldwide Information Systems internet: wex@pws.bull.com "Politics is Comedy plus Pretense."