Comments inline:
Mark Hood wrote:
Date: Mon, 10 Mar 2003 10:51:21 +0000 From: Rob Nugent <[EMAIL PROTECTED]>
1) Picking appears to only pick things below current Switch positions. This is annoying, since I use DistanceLODs with my Switches. I'd like to pick my most 'detailed' geometry all the time, but I get the 'crude' geometry if the primary ViewPlatform is far enough away. (This appears to me to help explain why a billboard always faces the primary view platform)
2) Picking appears to *always* succeed on geometry below a ViewSpecific group. This makes a certain amount of sense, since there is only one call to the behaviour for all Views. I'm now exploting this combined with my Switches/DistanceLODs to ensure that I can always pick from my most detailed geometry.
I can't find any documentation of 1) and 2).
The semantics of multiple views are still somewhat fuzzy in the Java 3D 1.3 architecture. For the most part they work, but we were always planning to clean them up for post 1.3 work. Some issues:
Problems with certain types of behaviors (e.g., ViewPlatform entry/exit, Billboard, LOD) that rely on per-View information, and with behaviors in general as far as scheduling (the view platform determines the active behaviors), and consistent updates to the scene graph.
LOD under SharedGroup and in multiple views.
I hate to say it, but it's probably best not to rely on the behavior you observed in point 2) carrying over to future Java 3D releases, since you're in a gray area with respect to your use of multiple views.
Of course we would strive for backward compatibility as far as possible. Probably the best way to ensure this is to submit a bug report for point 1) if you think it's a bug, and to submit a Request for Enhancement (RFE) for
I can't say that 1) is a bug, since the way picking works is so fuzzily defined. What I'd really like is an official way to be able to do picking independent of any View. i.e. use a PickRay/PickSegment to test for an intersection with geometry where the PickRay is unrelated to *any* ViewPlatform. I'd like to be able to pick from my most detailed model, but still use DistanceLODs to improve rendering performance.
point 2) with respect to clarifying the semantics of picking behaviors on multiple views and and how you think they ought to work.
I'm using 2) as a way round the lack of ability to pick from my most detailed geometry when using DistanceLODs. If this issue were resolved, I'd happily scrap the ViewSpecificGroup approach.
I suspect that I'm best raising a single RFE for all this - I'll try to do this.
Thanks for your input.
Rob
-- Mark Hood
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--
Rob Nugent Sun Microsystems, Southampton, UK
[EMAIL PROTECTED]
Tel: +44 (0) 1489 585503 Fax: +44 (0) 1489 881363
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