ESM4714
Scientific Visual Data Analysis and Multimedia
Exercise #10: Glyph Representation of Physical Properties

Many physical properties can be written as second order, fourth order, or higher order tensors. In the class handout "Three Visual Methods: Gradients, Function Extraction, and Tensor Glyphs", we explained how to construct visual representations of second and fourth order tensors. In this exercise we will introduce you how to construct simple 3D objects. With the skills you learn in this exercise you should be able to construct any 3D object, but here we start with simple 3D objects.

NOTE: Highlighted italic text denotes user response.

Objective: We start by constructing a simple four-sided tetrahedron.

Procedure:

  1. Logon onto mercury -> pluto.smvc.vt.edu at the VT-CAVE classroom (SMVC).

  2. Mount your optical disk (see procedure for mounting scsi devices).
  3. Go to the ESM4714/examples directory.

  4. Locate the directories that contain PV-Wave procedure files for generating a simple box, tetrahedron, and a sphere.

    viz?% cd /optical/ESM4714/examples/poly
    viz?% ls -lag 
    drwxr-xr-x   6 kriz     staff        512 Jan 11 20:35 .
drwxr-xr-x  13 kriz     staff        512 Jan 11 20:35 ..
drwxr-xr-x   2 kriz     staff        512 Jan 11 20:35 box
drwxr-xr-x   2 kriz     staff        512 Jan 11 20:35 glyph
drwxr-xr-x   2 kriz     staff        512 Jan 11 20:35 sphere
drwxr-xr-x   2 kriz     staff        512 Jan 11 20:35 tetra

  5. Go into the tetra directory, start wave, and construct a rotating tetrahedron by executing the following PV-Wave procedure files.

    viz?% cd tetra
    viz?% wave ; start up PV-Wave
    wave> rotate,37,10 ; create a sequence of 37 images rotated at 10 degrees increments and stored in the file rotate.byt.
    wave> movrot,37 ; play back rotate.byt image sequence.
    wave> picture,14 ; make a postscript file of the 14th image.

    NOTE: You can temporarily stop the rotation by using the middle mouse button and resume rotation by pressing the right button or terminate the procedure all together with the left mouse button.

  6. Create you own glyph of an icosahedron by copying all procedure files from the tetra directory to the icosa directory and creating the necessary vertice and polygon files from the class handout table of Hill's Appendix A8.1.5. Copies of the tetra data set files and procedure files will also be passed out in class.

    viz?% pwd --> /optical/ESM4714/examples/poly/tetra
    viz?% cd ..
    viz?% mkdir icosa
    viz?% cd tetra
    viz?% cp *.pro ../icosa

    NOTE: you may want to rename files with icosa instead of tetra. You may have also noticed that the polygon files must use vertice numbers beginning with the number zero "0" and not the number one "1". PV-Wave arrays always start with zero "0".
Click image to return to Visualization home page.
R.D. Kriz
Virginia Tech
College of Engineering
Revised 01/10/99

http://www.sv.vt.edu/classes/ESM4714/exercises/exer10/exer10.html