Lee,
(and SUN). Even more worrying is that this was an InvocationTargetException,
thrown by the reflection API. I find it extremely troubling that Java 3D
(high performance?) should be using reflection to invoke methods...
Daniel Selman
[EMAIL PROTECTED]
Tornado Labs Ltd.
http://www.tornadolabs.com
-----Original Message-----
From: Discussion list for Java 3D API
[mailto:[EMAIL PROTECTED]]On Behalf Of J. Lee Dixon
Sent: Thursday, February 22, 2001 2:03 PM
To: [EMAIL PROTECTED]
Subject: Re: LocalToVworld transform and deriving from Node
I had already tried using an empty Shape3D. I got the following
exception. Doesn't work for me. It doesn't make sense that Shape3D
should die like this... I think it's a bug.
Invocation Target Exception null
java.lang.reflect.InvocationTargetException:
java.lang.IndexOutOfBoundsException: Index: 1, Size: 1
at java.util.ArrayList.RangeCheck(ArrayList.java:491)
at java.util.ArrayList.get(ArrayList.java:307)
at
javax.media.j3d.Shape3DRetained.shapeIsMergeable(Shape3DRetained.java:17
45)
at
javax.media.j3d.Shape3DRetained.merge(Shape3DRetained.java:1715)
at javax.media.j3d.GroupRetained.merge(GroupRetained.java:1788)
at
javax.media.j3d.TransformGroupRetained.compile(TransformGroupRetained.ja
va:308)
at
javax.media.j3d.GroupRetained.compile(GroupRetained.java:1761)
at
javax.media.j3d.TransformGroupRetained.compile(TransformGroupRetained.ja
va:285)
at
javax.media.j3d.GroupRetained.compile(GroupRetained.java:1761)
at
javax.media.j3d.BranchGroupRetained.compile(BranchGroupRetained.java:146
)
at
javax.media.j3d.BranchGroupRetained.compile(BranchGroupRetained.java:121
)
at javax.media.j3d.BranchGroup.compile(BranchGroup.java:82)
-Lee
-----Original Message-----
From: David Schachter [mailto:[EMAIL PROTECTED]]
Sent: Thursday, February 22, 2001 3:33 PM
To: [EMAIL PROTECTED]
Subject: Re: [JAVA3D] LocalToVworld transform and deriving from Node
Use a Shape3D with no geometry or appearance (that is, use the default
constructor for Shape3D, not a constructor that takes parameters--or, if
you've over forty, arguments.) Without geometry and appearance, there's
nothing to render.
I had a similar problem over the weekend and the above is how I solved
it.
It's handy to have a debug switch that replaces the empty Shape3D with a
ColorCube or other visible object, to serve as a proxy for the invisible
object. The proxy makes 3D placement problems easier to find and fix.
It's also handy to have a a continuous intravenous drip of dark Belgian
chocolate, but that's a different topic.
BTW, the Java3D API specification mentions a flag for rendering
"invisible" objects but there's no useful description of what that
means. What's the spec talking about, in section C.5.5, "Visibility
Policy," page 518 of The Java 3D(tm) API Specification, Second Edition,
by Sowizral, Rushforth, and Deering?
-- David Schachter
At 02:33 PM 2/22/2001 -0500, J. Lee Dixon wrote:
>I am trying to implement animated cameras, but I am having a little
>trouble. First, a camera really has no shape, so I implement the camera
>as a TransformGroup. In order to make the call to getLocalToVworld(),
>the node in question must be live. Well, if I don't put a shape
>underneath the TransformGroup, then it never becomes live. Sounds like
>good optimization, but I need to know the transform for this "undrawn"
>entity.
>
>I could put a Shape3D with a single point and then give it rendering
>attributes to make it hidden, but that seems kludgy (BTW, this IS the
>correct spelling according to dictionary.com). ;)
>
>I even tried to make my own "EmptyNode", derived from the base class
>"Node". But when I tried to addChild(), I got:
>
>java.lang.reflect.InvocationTargetException:
>java.lang.NullPointerException
> at
>javax.media.j3d.GroupRetained.checkValidChild(GroupRetained.java:393)
> at
>javax.media.j3d.GroupRetained.addChild(GroupRetained.java:406)
> at javax.media.j3d.Group.addChild(Group.java:261)
> ... yadda yadda
>
>Any suggestions??
>
>J. Lee Dixon
>SAIC - Celebration, FL
>407-566-1438
>[EMAIL PROTECTED] AOL: LeeOrlando
>
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