That depends on how you construct your app & models. Yes, if you have a fast computer, then picking can solve many things. If you have lots of memory, then you can solve also the problem of garbage collection. Just disable it. Otherwise try to make compromises. Use picking if it is appropiate. Use other methods where possible. I'm not saying anything about your app, because I don't know your app. Hope to see it soon on the net, because the picture you posted looked really neat. I was only giving my 2cents opinion.
Cheers, Florin -----Urspr�ngliche Nachricht----- Von: Rob Nugent [mailto:[EMAIL PROTECTED]] Gesendet: Freitag, 21. Februar 2003 13:53 An: [EMAIL PROTECTED] Betreff: Re: [JAVA3D] AW: [JAVA3D] AW: [JAVA3D] Advantages of picking over consulting the actual geometry Florin, This is horses-for-courses obviously, and which to choose will depended on the app concerned. For *my* app, I want the moving of the objects to be sensitive to the actual geometry of the scene. If I move to a 'simplified model' I have the burden of maintaining that model, and it doesn't do all the things I want to without making that model of the same complexity as my geometry. (e.g. a door in one of my buildings opens until it hits something). My point is that the picking routines *are* fast enough to do this (with appropriate construction of the scene graph), for those of for whose apps it is necessary. There is the side-issue of the garbage generated under some circumstances, but this isn't significant enough for me to want to compromise my collision model. Rob Florin Herinean wrote: > As you say, it's valid to use it every frame and so on, but I wouldn't do > it. For the type of thing you are doing, as I could see from your posted > image, I would use a simplified model to do the picking, eventually an > *extremely* simplified model, like a b&w height bitmap. Knowing the distance > to the ground will be simply a lookup into a table based on x-y, avoiding > completely the picking mechanism. > > Cheers, > > Florin > > -----Urspr�ngliche Nachricht----- > Von: Rob Nugent [mailto:[EMAIL PROTECTED]] > Gesendet: Freitag, 21. Februar 2003 13:07 > An: [EMAIL PROTECTED] > Betreff: Re: [JAVA3D] AW: [JAVA3D] Advantages of picking over consulting > the actual geo metry > > > Florin, > > The trouble is that the Locale.pickAll() and Shape3D.intersect() is that > they > are essentially the *only* mechanisms provided by Java3D for testing for > intersections between ray, segment, etc and geometry in the scene. > > Yes, calling these from a user interaction as a result of a mouse click is a > common use case. However, it is entirely valid that I should e.g. want to > pick > the object under my view platform every frame or use these routines to do > collision detection. They are the only capabilities provided by Java3D that > allow me to do this, and the garbage they produce can easily be excessive. > > Rob > > Florin Herinean wrote: > >>I think that "picking" should simply do that. I mean you move the mouse > > over > >>the screen, and "pick" something. In that case you need the whole picking >>framework, and since the picking is done only when you click the mouse, it >>shouldn't generate so much garbage. After all, how quickly can you click > > the > >>mouse buttons ??? For the rest like terrain following and maybe collision, >>the program itself can be constructed so that it can be really very >>efficient, without the picking framework, as was posted before. >> >>However, I do see one circumstance when you can use picking for terrain >>following, when you don't know anything about the terrain. You navigate > > over > >>a terrain which was provided by a 3rd party program and you or your > > program > >>doesn't have a single clue of how it looks like. >> >>Cheers, >> >>Florin > > > To unsubscribe, send email to [EMAIL PROTECTED] and include in the body > of the message "signoff JAVA3D-INTEREST". For general help, send email to > [EMAIL PROTECTED] and include in the body of the message "help". -- Rob Nugent Sun Microsystems, Southampton, UK [EMAIL PROTECTED] Tel: +44 (0) 1489 585503 Fax: +44 (0) 1489 881363 =========================================================================== To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff JAVA3D-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help". ==========================================================================To unsubscribe, send email to [EMAIL PROTECTED] and include in the body of the message "signoff JAVA3D-INTEREST". For general help, send email to [EMAIL PROTECTED] and include in the body of the message "help".
