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3D rendering question

  • To: mathgroup at
  • Subject: 3D rendering question
  • From: jdock%iplab5 at (Jerry Dougherty)
  • Date: Mon, 16 Nov 92 15:00:56 EST

Question: Is there anyone out there who is working on 3D rendering?

I have a series of X-Y plots which correspond to X-Y planes along the Z-axis.

I would very much like to connect these plots together to form a region.

I have used the StackGraphics[ ] command from the Graphics`Graphics3D` package

to give myself an idea of what this region might look like, but would REALLY 

like to render it in polygons.

I have been trying to use the TriangularSurfacePlot[ ] command from the 

DiscreteMath`ComputationalGeometry`  package but have been unsucessful to date.

Essentially what I've done with TriangularSurfacePlot[ ] is the following:

1. For each X-Y plot I grabbed the 2D list of points from the InputForm of
   the graphics{{xi,yi},{xj,yj},...}

2. I then appended the corresponding z value to the end of each point in the   
   list, there by creating a list of 3D{{xi,yi,z1},{xj,yj,z1},...}

3. I combined all the lists together to give me the desired list of points to 
   be connected.
  ie. list = {{xi1,yi1,z1},{xj1,yj1,z1},...{xi2,yi2,z2},{xj2,yj2,z2},...}

4. I proceeded to try TriangularSurfacePlot[list] ,but my SPARC IPX goes nuts
   and the process usually core dumps, not to mention all the error messages!!

5. So I reduced the problem down to two circles one with radius 1 and one with
   radius 2. I assume these are X-Y planes placed at z = 3,and z = 5 resply.
   Well this didn`t work either. I finally tried two triangles and had some
   success but the problem is reduced to not being useful anymore.

6. I've also played around with the vertex adjacency list option but it seems 
   in order for the list to work properly you have to practically specify 
   every connection making sure to form triangles along the way,  yuck!!

Anyway  if you get anything I've said and have any suggestions what-so-ever
it would be Greatly appreciated......

Thanks in advance....jdock at

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