Florin, It was my understanding that geometry by reference simply allows one to hand geometry to a shape3d, without requiring the shape3d to make its own internal copy. Therefore, it eliminates the need for a copy operation.
I dont believe that any indirection is added. A reference to geometry is always needed somewhere, regardless of if that geometry is a copy or an original. Therefore, I dont believe that by reference, performance is negatively impacted. Further, I dont believe this has anything to do with updating geometry. Geometry can always be updated, unless the branch group is compiled. Thoughts? Ian On Mon, 6 Jan 2003, Florin Herinean wrote: > Using geometry by reference only makes sense when you want to modify the > geometry at runtime, otherwise you just introduce another level of > indirection and hinder possible optimizations. > > Cheers, > > Florin > > -----Ursprüngliche Nachricht----- > Von: Ian M Nieves [mailto:[EMAIL PROTECTED]] > Gesendet: Montag, 6. Januar 2003 09:55 > An: [EMAIL PROTECTED] > Betreff: Re: [JAVA3D] size of transform3D and transformGroup > > > Hans, > > Thanks for your reply. Your point is very clearly made. > > I may be in trouble though. I might want to be able to share geometry, > but have different appearances. I will have to look into this more. > > Another question though. Is is possible for me to use geometry and > normals, by reference (instead of by copy), and have each reference point > to a single, shared static version of the geometry and normals? Would > that have any effect? > > Thanks,Ian > > > On Sun, 5 Jan 2003, Hans Horn wrote: > > > Ian, > > > > I don't know about the individual memory reqs of Transform3D and > > TransformGroup, but I do know from my own projects by experimenting with > > SharedGroups, that the SharedGroup approach is the way to go with clear > > advantanges in the construction time of the scene, the memory footprint > and > > the performance of the final scene. > > > > In one of my previous projects I built a J3D molecular viewer where I can > > turn on the use of SharedGroups for > > atoms (Primitive=Sphere) and bonds (Primitive=Cylinder) explicitly. > > When loading a 1500 atom molecule, the whole app requires about 30MByte of > > memory with SharedGroups, but without I quickly run out of the 128MByte > > memory I give to the JVM. > > For a smaller molecule of say 100 atoms, where I can get thru with doing > it > > both ways, I find the construction time with SharedGroups about half > > compared to when using no SharedGroups. Also, the scene is much more > > responsive to mouse operations when using SharedGroups. > > > > I found, however, that SharedGroups have their limitations, too. If you > need > > to be able to pick an individual object in the scene and do some special > > rendering (e.g. change its appearance) on it depending on its picked > state, > > it must not be in a SharedGroup, as all items in the group share the same > > appearance. > > > > H. > > > > > =========================================================================== > > 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". > > =====================================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".
