Gary,
Use a Raster. It will probably be quite slow (guessing). I'd expect picking
to be faster.
Sincerely,
Daniel Selman
[EMAIL PROTECTED]
http://www.tornadolabs.com
> -----Original Message-----
> From: Discussion list for Java 3D API
> [mailto:[EMAIL PROTECTED]]On Behalf Of Gary L. Graf
> Sent: 27 January 2000 22:31
> To: [EMAIL PROTECTED]
> Subject: Re: [JAVA3D] Pixel Coordinates to Model Coodinates
>
>
> I agree with your comments. I will be the first to admit that
> I am not a
> professional Java3D developer but right off hand I don't know how
> to access the
> depth of the z-buffer at the desired x-y location. It seems to
> me that without
> it you will have to run down the line of sight until you find the
> first object,
> which is what I was trying to explain. The z-buffer data could
> give you that
> easily. Does anyone out there know how to get the data?
> Gary
>
> [EMAIL PROTECTED] wrote:
>
> > > Hi,
> > > The problem is that the redering process necessarily
> > > looses information
> > > in the conversion from 3D to 2D and there is no way to go back and
> > > explicitly reconstruct it.
> >
> > Forgive my ignorance, I've never written a line of Java 3D,
> >
> > All you need is the inverted projection matrix,
> > the screen coordinates, and the
> > depth value from the z-buffer to reconstruct the world
> > coordinates of your object. You'll lose some precision
> > depending on your depth range, but for close objects
> > you'll get pretty good values. Does java 3D not provide
> > access to that information?
> >
> > Thanks,
> >
> > Vann
> > --
> > Vann Hasty
> > Real-time rendering
> > Evans & Sutherland
> >
> >
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