>Actually the bounds compute is just bigger and not technically not wrong
>as long as it enclose the geometry.
>  Java3D specification didn't enforce the tightest bounds on the
>geometry. So GEOMETRY based picking (instead of BOUND based picking)
>should always use in your case.
>
You are right, technically, but if we can get more accurate bounds, that's
very useful. When I first tried to rotate my objects around its center, it
always moves outside of the screen. When I do the Fit in View, I also need
more accurate center and radius. Anyway, it's not a big deal, I have my own
class to do it.

>
>
>The specifiction did not mention this case clearly. But if you use
>PickPoint for Geometry picking in the API it will throw Exception will
>the following message
>"PickPoint doesn't make sense for geometry-based picking. Java 3D
>doesn't have spatial information of the surface. Should use PickBounds
>with BoundingSphere and set radius to a epsilon tolerance."
>
>The utility library should output this.

Now, I have a better idea of all the Picking classes, thank you for your valuable 
information.

>It is not uncommon for ray fail to detect interesting with the side of
>triangle due to numerical error. setting pickTolerance will not work
>since this only affect how the shape is defined in PickTool for picking.
>It will not affect the second call when pickshape is explicitly defined.
>Use
>        PickCylinderRay pp = new PickCylinderRay(localPt, new Vector3d(0, 0, 1),
>0.1f);
>
>should work in your case.
>
>- Kelvin
>
>---------------------
>Java 3D Team
>Sun Microsystems Inc.
>
PickCylinderRay works, but it may pick more than I need.

The PickRay always fails. If I pick (0,1,0), it always get the right part for the 2nd 
pick call, if I pick (0,-1,0), it fails to pick any one for the 2nd pick call.  If I 
were implementing the PickRay, I think I still need to use something like distance 
tolerance inside although I may not allow user to specify it.

Thank you very much!

white

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