[comp.graphics.visualization] Visualization of vector and tensor fields

corkum@csri.toronto.edu (Brent Thomas Corkum) (02/15/91)

What I'm looking for is some input on what sort of algorithms people 
are using for the visualization of vector and tensor (stress) data. 

My data is on a regular 3D grid (Elastic Boundary Element Analysis) and I'm 
currently using marching cubes to visualize the individual scalar components
of the tensor.  What I would like to do is implement a fairly intuitive
visualization technique for looking at the principal stresses AND directions
(eigenvalues and eigenvectors of the tensor matrix).

 Does anyone have any insightful ideas on how to do this? Currently I'm
contimplating drawing 3-D vectors with lengths and/or colors indicating
the magnitude of the stress vectors. I've seen some plots of this sort
of thing though and find it very cluttered and hard to understand, 
especially if there are three principal vectors at a point that you 
wish to plot.

Brent Corkum
Civil Engineering
University of Toronto
corkum@boulder.civ.toronto.edu
Hardware Platform: SGI 4D/25T 

corkum@csri.toronto.edu (Brent Thomas Corkum) (02/16/91)

This is a followup on my previous posting. So far I've got a few
replies, all seem to suggest plotting an ellipsoid with axis
oriented with the eigen vector directions and lengths equal to the
magnitudes.  I suppose it could be any geometric shape with three
principal directions. Since my system is polygon based I'd be more
inclined to use a more simplistic shape.  Another suggestion was flow
fields or tracers, like those used in CFD visualizations. I'd like to
here more from people using tracers on what the best system of color
and complexity yields the best visualization. Anyways, if I get enough
replys I'll make them available through ftp, so if anyone doesn't
want me to post there response let me know.

Brent Corkum
corkum@boulder.civ.toronto.edu