RE: [Algorithms] Ray picking in editors - best done with collision volumes, or visual volumes?
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From: Tom F. <tom...@ee...> - 2004-11-26 04:19:28
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One thing that helps is to always highlight in some small way the thing under the mouse - also print its name in a status bar or something. That = way when the user clicks on something, they're pretty sure they're clicking = on the right thing. Once you have that, people get pretty used to "dodging" = or "catching" the AABB, even if it's not displayed directly. TomF. > -----Original Message----- > From: gda...@li...=20 > [mailto:gda...@li...] On=20 > Behalf Of Rowan Wyborn > Sent: 25 November 2004 20:13 > To: gda...@li... > Subject: RE: [Algorithms] Ray picking in editors - best done=20 > with collision volumes, or visual volumes? >=20 >=20 > my 2 cents: >=20 > - picking in an editor must be per poly. if you just use BV's=20 > only, things get to be a pain when you are dealing with=20 > densely packed objects and/or manipulating the scene from a=20 > distant viewpoint >=20 > - as you say, not all objects have collision data. so its=20 > best to just use the triangle render data. you can quickly=20 > whip up some simple raycast routines specifically for the=20 > editor (eg linear iteration through all polys in an=20 > object)... they dont need to be uber fast coz you arent=20 > stressing them in realtime use >=20 > rowan >=20 > > -----Original Message----- > > From: Megan Fox [mailto:sha...@gm...] > > Sent: Friday, 26 November 2004 2:29 PM > > To: gda...@li... > > Subject: [Algorithms] Ray picking in editors - best done with=20 > > collision > > volumes, or visual volumes? > >=20 > >=20 > > It seems like either could work, but both appear to have (fairly > > major) drawbacks, so I'm curious what others have done here. > >=20 > > On the one hand, I could use my visual bounding volumes for the > > picking. This has the advantage that anything visible can=20 > be selected > > and worked with, but my concern is that my visual bounding=20 > volumes are > > generally not that accruate - they're just a best-fit AABB per mesh, > > that's it. It seems like I'll have tons of cases where it becomes > > difficult to select one object due to another piece of intersecting > > cruft (like a particle fountain or light object or whatever). > >=20 > > On the other hand, I could go with ray picking via my collision > > routines. This has the advantage of fairly accurate bounds for all > > the objects, but carries the significant disadvantage that just not > > everything is going to BE collidable. Now I suppose I could get in > > the habit of always defining a collision volume for an=20 > entity "just to > > be thorough", even if said volume was just a trigger-type=20 > sphere, but > > this strikes me as fairly wasteful. I could also get in=20 > the habit of > > keeping collision data around for these visual-only=20 > entities but only > > using it when editing, except then I'm maybe just wasting=20 > effort when > > I should just go with the pre-existing visual AABBs. > >=20 > >=20 > > What have people used in their engines, and which ends up=20 > being "good > > enough"? This doesn't have to be pixel-perfect, my artist is just > > getting tired of typing entity names into the console manually every > > time he wants to toy with their position or a value ;) > >=20 > >=20 > > Thanks, > > -Megan Fox > >=20 > >=20 > > ------------------------------------------------------- > > SF email is sponsored by - The IT Product Guide > > Read honest & candid reviews on hundreds of IT Products from=20 > > real users. > > Discover which products truly live up to the hype. Start=20 > reading now.=20 > > http://productguide.itmanagersjournal.com/ > > _______________________________________________ > > GDAlgorithms-list mailing list > > GDA...@li... > > https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list > > Archives: > > http://sourceforge.net/mailarchive/forum.php?forum_id=3D6188 > >=20 >=20 >=20 > ------------------------------------------------------- > SF email is sponsored by - The IT Product Guide > Read honest & candid reviews on hundreds of IT Products from=20 > real users. > Discover which products truly live up to the hype. Start reading now.=20 > http://productguide.itmanagersjournal.com/ > _______________________________________________ > GDAlgorithms-list mailing list > GDA...@li... > https://lists.sourceforge.net/lists/listinfo/gdalgorithms-list > Archives: > http://sourceforge.net/mailarchive/forum.php?forum_ida88 >=20 |