AppletTalk.com Java discussions newsgroups   Archives   FAQ   Search   Memberlist   Usergroups   Register   Profile   Log in to check your private messages   Log in  Scheduling Bounds of a Behavior          AppletTalk.com Forum Index -> 3D Graphics API's for Java View previous topic :: View next topic   Author Message Thomas Partsch Guest Posted: Tue Dec 19, 2006 6:40 pm    Post subject: Scheduling Bounds of a Behavior Hi there! In Daniel Selmans book "Java 3D Programming" (ISBN 1930110359) there is an example given for scheduling bounds for a behavior (page 165): There is a behavior that rotates a wheel only if the car is within 20 meters of the viewer. That is, if the Bounds for the Behavior intersect the ViewPlatform's activation region. My question is now: What are the parameters for the Bounds? Radius is 20 meters, of course, but where is the origin of that BoundingSphere (considering it would be a BoundingSphere)? Regards, Thomas Back to top Matthias Guest Posted: Wed Dec 20, 2006 12:56 am    Post subject: Re: Scheduling Bounds of a Behavior On Tue, 19 Dec 2006 13:40:58 +0100, Thomas Partsch <thomas (AT) thomepage (DOT) de> wrote: Quote: My question is now: What are the parameters for the Bounds? Radius is 20 meters, of course, but where is the origin of that BoundingSphere (considering it would be a BoundingSphere)? Hi, I am totally guessing, but I would think the camera origin? hth Matthias ps. Is turning a car's wheels or not really so important performance-wise? I mean.. the wheels must be rendered no matter whether they turn or not. Back to top Thomas Partsch Guest Posted: Wed Dec 20, 2006 1:24 am    Post subject: Re: Scheduling Bounds of a Behavior Matthias schrieb: Quote: On Tue, 19 Dec 2006 13:40:58 +0100, Thomas Partsch thomas (AT) thomepage (DOT) de> wrote: My question is now: What are the parameters for the Bounds? Radius is 20 meters, of course, but where is the origin of that BoundingSphere (considering it would be a BoundingSphere)? Hi, I am totally guessing, but I would think the camera origin? hth Matthias ps. Is turning a car's wheels or not really so important performance-wise? I mean.. the wheels must be rendered no matter whether they turn or not. Hi Matthias! Don't ask me about performance. The example given is from the book. This is all about explaining Behaviors not writing a performant application. In Java 3D API Specifation it is said, that the ViewPlatform's activation region is a BoundingSphere around the ViewPlatform. If the Behavior is only activated if the Behavior's Bounds intersect the ViewPlatforms Bounds, I would guess, the Behavior's Bounds origin would be the origin of the wheel. Can you follow my thought? Back to top Matthias Guest Posted: Wed Dec 20, 2006 3:14 pm    Post subject: Re: Scheduling Bounds of a Behavior On Tue, 19 Dec 2006 20:24:36 +0100, Thomas Partsch <thomas (AT) thomepage (DOT) de> wrote: Quote: In Java 3D API Specifation it is said, that the ViewPlatform's activation region is a BoundingSphere around the ViewPlatform. If the Behavior is only activated if the Behavior's Bounds intersect the ViewPlatforms Bounds, I would guess, the Behavior's Bounds origin would be the origin of the wheel. Can you follow my thought? Hi Thomas as far as i understand the meaning of view platform is more or less what in some other 3d software is called camera meaning the location from where you are actually viewing your 3d scene: therefore your statement would imply that the BoundingSphere's origin is at your camera (essentially at the point your 'eyes' look at the 3d scene) and the Behaviour is activated when your wheels get close to your viewpoint. (So I think it is the other way round you described it above) However this is crude guessing, i'm here because i don't really know java 3d and because i want to learn a bit.. however this group is not very active greetings matthias Back to top sanbikinoraion Guest Posted: Wed Dec 20, 2006 3:50 pm    Post subject: Re: Scheduling Bounds of a Behavior Quote: My question is now: What are the parameters for the Bounds? Radius is 20 meters, of course, but where is the origin of that BoundingSphere (considering it would be a BoundingSphere)? Contrary to the other responders, I believe that the origin of the bounding sphere to get the desired effect should be the origin of the car. This is why: I believe that behaviours are triggered when their bounding sphere intersects the viewplatform's origin, rather than the other way round. Thinking about it, this is the way that makes sense: if you set the behaviour's origin to be that of the viewplatform, how would you know where the behaviour was located? For a car that may move around your scene graph you'll either have to have the behaviour update the origin of the scheduling bounds whenever it moves or use a bit of cleverness due to the way java will pass point3ds by reference rather than value: you can get the point3d that represents the origin of the car and set it to be the origin of the scheduling bounds. That way, whenever the car alters its own origin the scheduling bounds will automatically update themselves. Cheers, Kendrick Back to top Thomas Partsch Guest Posted: Wed Dec 20, 2006 7:08 pm    Post subject: Re: Scheduling Bounds of a Behavior sanbikinoraion schrieb: Quote: My question is now: What are the parameters for the Bounds? Radius is 20 meters, of course, but where is the origin of that BoundingSphere (considering it would be a BoundingSphere)? Contrary to the other responders, I believe that the origin of the bounding sphere to get the desired effect should be the origin of the car. This is why: I believe that behaviours are triggered when their bounding sphere intersects the viewplatform's origin, rather than the other way round. I said that, did I not? Quote: Thinking about it, this is the way that makes sense: if you set the behaviour's origin to be that of the viewplatform, how would you know where the behaviour was located? That was also my latest thought. Quote: For a car that may move around your scene graph you'll either have to have the behaviour update the origin of the scheduling bounds whenever it moves or use a bit of cleverness due to the way java will pass point3ds by reference rather than value: you can get the point3d that represents the origin of the car and set it to be the origin of the scheduling bounds. That way, whenever the car alters its own origin the scheduling bounds will automatically update themselves. Thanks a lot. Thomas Back to top Display posts from previous: All Posts1 Day7 Days2 Weeks1 Month3 Months6 Months1 Year Oldest FirstNewest First         AppletTalk.com Forum Index -> 3D Graphics API's for Java All times are GMT Page 1 of 1   Jump to: Select a forum Java Newsgroups----------------Java DiscussionsWeb-based java games comp.lang.java 3D Graphics API's for Java Java: Support and criticism Java System Announcements comp.lang.java.api JavaBeans Java and CORBA Java and Databases comp.lang.java.developer Java GUI Toolkits Java Help comp.lang.java.javascript JVM, native methods and hardware comp.lang.java.misc Java Language Programming Security and Java comp.lang.java.setup Java Software Tools comp.lang.java.tech ibm.software.java.linux  Non-English Java Newsgroups----------------Java Language (German)Language Java (Français)Java (Italian)  You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum Powered by phpBB © 2001, 2006 phpBB Group SEO toolkit © 2004-2006 webmedic.