Justin,

(Just got back from leave, and saw your append).

I've been experimenting in this area. I can't give a definitive answer, but here
are some of the things I observe. (Remember I'm not part of the J3D group, so
I'm in no privileged position).

Firstly, my scenario: I'm using a single WakeupOnElapsedFrames(0) behaviour with
two Canvas3Ds. I see a call to the behaviour, then separate calls to render each
Canvas3D (as observed by over-riding postSwap() etc in the two Views. I'm doing
my picking from the behaviour.

My observations:

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). If my observations are correct, I'd
really like to see this written does somewhere, as I am now substantially
relying on these observations.

Rob

Justin Couch wrote:
Anyone know what the details of the picking specification are? The J3D
Specification doesn't actually say anything about how they work, just
that you can pick stuff and get an answer. For example, does pick use
render traversal information or not? (is pickClosest() based on the the
OrderedGroup or Switch selection for example).

--
Justin Couch                         http://www.vlc.com.au/~justin/
Java Architect & Bit Twiddler              http://www.yumetech.com/
Author, Java 3D FAQ Maintainer                  http://www.j3d.org/
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Rob Nugent Sun Microsystems, Southampton, UK

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