Here is a suggestion for the next go round of Java 3D.... Perhaps there should be a formal recognition of a "display" space separate from the world space. That way objects such as Billboards, callouts, and other such display oriented objects that live with one foot in the 3D world and the other in the 2D world would work properly on a display-by-display basis. Such objects would be defined in world space the same as any 3D object but they would only appear in the display space of each view that had them in view, with each view processing them from its vantage point. Perhaps LOD could also be handled this way. Of special note, such a separation of display space from world space could also be made to handle overlay and layering, hopefully with control over the precedence of overlay according to which space the object came from: the world or the display space. A variation on this theme and a further generalization would be to also define a separate 3D "view" space associated with a view and its display. This would effectively be a 3D version of the separate 2D display space described above. --jon > An issue has been raised as to how multiple views are handled with LOD > and with Billboard behavior. As has been pointed out, the fact that > Billboard and LOD are behaviors that operate on the scene graph makes > it difficult to support multiple views, each with a different > orientation or level of detail. > > We realize that this is a hole in the current design and have added > the following new method to the Behavior node object to address this > issue. > > protected View getView() > > Returns the primary view associated with this behavior. This > method is useful with certain types of behaviors (e.g., > Billboard, LOD) that rely on per-View information and with > behaviors in general in regards to scheduling (the distance > from the view platform determines the active behaviors). The > "primary" view is defined to be the first View attached to a > live ViewPlatform, if there is more than one active View. So, > for instance, Billboard behaviors would be oriented toward this > primary view, in the case of multiple active views into the > same scene graph. > > This method will be part of the impending public early access release. > We will be releasing an updated API specification at the same time. > Subsequent versions of the API will address the issue of providing > more complete support for multiple views, but the current version is > somewhat limited in this respect. > > Hope this helps. > > - -- > Kevin Rushforth > Java 3D Team > Sun Microsystems -- ____________________ Peculiar Technologies ____________________ Jon Barrilleaux 3800 Lake Shore Ave. Purveyors of [EMAIL PROTECTED] Oakland, CA 94610 Alternate Reality 510.444.4370 voc Augmented Simulation 510.444.0231 fax www.augsim.com and 3D Solutions
