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<P>George,</P>
<P> On the OpenGL site (<A href="http://www.opengl.org/">http://www.opengl.org/</A>) there is code to do real-time shadows (15 frames per second on an SGI). Try their search with: "real time shadows" It is implemented as a "library" on top of OpenGL. </P>
<P>You might solve your immediate problem by working directly with the OpenGL code. But if you already use vtk, or think you might, I would suggest adding it to vtk (he says shamelessly!). </P>
<P>Given that vtk is primarily (soley?) based on OpenGL, I think this could be added to vtk <EM>relatively</EM> painlessly. The main effort would probably be in getting it packaged correctly in keeping with the vtk architecture and class hierachy, ...which would require a pretty good understanding of how the vtk renderer works... so ok, some pain... but the resident gurus on the list are very helpful...</P>
<P> fingers crossed...</P>
<P> Dave Pont</P></DIV>
<DIV></DIV>
<DIV></DIV>>From: Gharrison9@aol.com
<DIV></DIV>>To: vtkusers@public.kitware.com
<DIV></DIV>>Subject: [vtkusers] Shadows
<DIV></DIV>>Date: Wed, 16 Jan 2002 20:15:00 EST
<DIV></DIV>>
<DIV></DIV>>In the Visualization Toolkit 2nd Edition book I see that in plate 62
<DIV></DIV>>regarding the Computational fluid dynamics visualization there are shadows.
<DIV></DIV>>I would like to know how this is done.
<DIV></DIV>>
<DIV></DIV>>On on one of our projects we are working on animating a tower crane sitting
<DIV></DIV>>on a 2D in 3D surface where we would like the entire assembly to have shadows
<DIV></DIV>>on the ground -- as we turn the crane. This can be done of course with raw
<DIV></DIV>>calculations, but since we are rendering within each animation, we don't want
<DIV></DIV>>to extensive calculations to effect significantly the speed or rotation.
<DIV></DIV>>
<DIV></DIV>>Any ideas are appreciated. I suspect that this is either a trivial problem
<DIV></DIV>>or extremely complex.
<DIV></DIV>>
<DIV></DIV>>George
<DIV></DIV>>
<DIV></DIV>>
<DIV></DIV>>George C. Harrison Professor of Computer Science
<DIV></DIV>>Norfolk State University
<DIV></DIV>>Telephone: 757-823-8654
<DIV></DIV>>Fax: 757-823-9229
<DIV></DIV>>email: gcharrison@nsu.edu
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