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From: naughton@wind.Sun.COM (Patrick Naughton)
Newsgroups: comp.graphics
Subject: Virtual Sphere - 3D Object Manipulator
Keywords: virtual sphere 3D rotation
Message-ID: <124673@sun.Eng.Sun.COM>
Date: 14 Sep 89 00:12:59 GMT
Sender: news@sun.Eng.Sun.COM
Reply-To: naughton@sun.com (Patrick Naughton)
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Organization: Sun Microsystems, Mountain View
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The August '88 SIGGRAPH proceedings describe an algorithm for manipulating
3D objects in an intuitive manner with a 'virtual controller'.

   Chen, Mountford and Sellen, "A Study in Interactive 3-D Rotation Using
   2-D Control Devices", Computer Graphics, Vol 22, No 4, August 1988.

It basically describes the transforms required to turn the 2-D delta motion
from a mouse dragged over the window displaying the object into the 3-D
rotation about an arbitrary axis in 3-D space.  It models this as a virtual
sphere or track-ball centered at the center of the object to be manipulated.

I am looking for someone who has already coded this from the algorithm to
C or some other reasonable language in any form of a window system.

I am playing with spinning 3D objects around using a NeWS front end under
OpenWindows while talking directly to the GX hardware on my 4/60 and don't
want to waste a lot of time rebuilding this particular wheel if it is
already out there.

I'll go ahead and do it myself if I don't hear from anyone and post it to
this group, but this is a pet project not real work, so it may be a while.

-Patrick
    ______________________________________________________________________
    Patrick J. Naughton				    ARPA: naughton@Sun.COM
    Window Systems Group			    UUCP: ...!sun!naughton
    Sun Microsystems, Inc.			    AT&T: (415) 336 - 1080