SYNOPSIS

3-D display of triangulated mesh with contour surfaces

SYNTAX 

    	 cvrti   -options (nnn)  filename

DESCRIPTION

A program for displaying both geometry and data assigned to the nodes of a geometry in an interactive way on a Silicon Graphics workstation. This program will only create graphics on a machine that includes the GL library, but the code is located on aepbme and seymour.

FLAGS

-B
select a border bounding box at startup
-b
select a border boundary drawn as lines at startup
-c nnn
select a color scheme
-C nnn
select the contour drawing mode
-CS
start the contours in filled mode
-D
select points displayed
-db
open the graphics window in double buffer mode
-F nnn
select frame mode and set the first frame number
-G nnn
select frame mode and set the last frame number
-L nnn
select the initial number of contour levels
-M
select the triangle mesh at startup
-sx nnn
set the window origin in x
-sy nnn
set the window origin in y
-P nnx
select the initial value for contour scaling, maximum
-Q nnx
select the initial value for contour scaling, minimum
-R nnx
initial potential value for the selected contour level
-sx nnn
set the window dimensions in x
-sy nnn
set the window dimensions in y
-V
select vectors displayed mode
-wt string
set the window title
-W nnx
set the line width for lines drawn here
-X nnx
set the viewpoint rotation angle for x
-Y nnx
set the viewpoint rotation angle for y
-Z nnx
set the viewpoint rotation angle for z
-zp
draw a 2-D map as a raised 3-D contour map

File Description

cvrti accesses input files which describe the geometry of the mesh and the parameter values to be used in the construction of contour lines. These files are each ASCII lists, with a single record per line.

The user must provide filename.pts which should contain 3 floating point values for the x,y,z coordinates of the nodes in the mesh. If this is the only file provided, cvrti will not attempt any mesh or contour presentation. Only the coordinates of the nodes in space will be presented.

The user may optionally provide filename.fac which should contain 3 long integer values for the nodes which form each triangle in the mesh. If this file is provided, cvrti will allow mesh presentation showing connections between the nodes.

The user may optionally provide filename.pot which should contain 1 floating point value for each node in the mesh. If this file is provided, cvrti will generate contour lines based on the parameter values and the mesh connections.

The user may optionally provide filename.vec which should contain 2 integer values for each ``additional lines/vectors'' to be drawn. These values must be node numbers in the points file.

FLAG Parameter Description

For FLAGS in which nnn is included, the user must supply an integer number. For FLAGS in which nnx is included, the user must supply a floating point number.

Contour Mode Description

nnn=0
draw only the selected contour line or surface
nnn=1
draw all contour lines - highlight min,max,selected
nnn=2
minimum contour level
nnn=3
draw single contour surfaces with banded faces
nnn=4
draw all contour surfaces with banded faces
nnn=5
draw all contour surfaces with volor blending
cvrti allows contour lines/surfaces to be displayed in a number of different modes

Frame Mode Description

cvrti includes a frame mode in which a series of filename.pot files can be accessed. In this mode, each frame consists of a set of contour lines unique to the frame. To use frame mode, the starting frame number and the ending frame number must be specified with the -F and -G flags.

Color Schemes 

nnn    	selected  unselected  minimum  maximum  mesh    mesh
	contour   contour     contour  contour points triangle vectors bound window
	line	  lines	      level    level

0	black  	  gray        gray     gray	gray	gray	gray	gray  white
1	white	  blue	      yellow   black    green   red     red     green mid-blue

5	yellow	  yellow      white    blue     green   red     red     green mid-blue
6	black	  black	      white    blue	green   red     red     green mid-blue
7	white	  white	      blue     white	green   red     red     green mid-blue
8	white	  white	      yellow   black	green   red     red     green mid-blue

10 	white	  blue	      white    black    green   red     red     green mid-blue
Control of cvrti after the program is initialized is by the use of keyboard, mouse, and dials events. Below are tables of all the current control devices and their function.

Dial Box

Dial 0 (Bottom left)
NOT IMPLEMENTED
Dial 1 (Bottom right)
NOT IMPLEMENTED
Dial 2 (2nd row left)
Z-rotate
Dial 3 (2nd row right)
NOT IMPLEMENTED
Dial 4 (3rd row left)
Y-rotate
Dial 5 (3rd row right)
NOT IMPLEMENTED
Dial 6 (top left)
X-rotate
Dial 7 (top right)
NOT IMPLEMENTED

Mouse Controls

Left Mouse Button
Rotate about x and y
Middle Mouse Button
Scale the image
Right Mouse Button
sgi window manager

Keyboard

A
Animate through contour surfaces
B
Toggle bounding border draw
C
Toggle contour draw
F
Animate through frame contours
H
Help and command display
I
Reset the frame and contour surface counters
M
Toggle mesh draw
P
Toggle point draw
Q
Quit program
R
Reset to startup conditions
S
Toggle fsolid/blended color draw for pts, fac, vec
V
Toggle adtitional vectors draw
W
Write an image to an RGB file
Z
Write all images from an animation to sequence of rgb files
Left Arrow Key
Rewind one image
Right Arrow Key
Advance one image
Up Arrow key
Advance one surface
Down Arrow Key
Rewind one surface

EXAMPLES 

1. cvrti test
This will invoke cvrti for the files with filename=test using all default values. If there id no test.pot file, then the screen will be blank. By issuing keyboard commands, features will be brought into the window. 
2. cvrti -b -c 0 -C 1 -L 100 -P 200 -Q 0  test
This will invoke cvrti for the files with filename=test using a bounding line for the border, a black and white color scheme, all contour levels drawn, with 100 contour levels scaled at 2.0 increments between 0 and 200.0 
3. cvrti  -B -c 1 -L 100 -P 100 -X 300.0 -Z 350.0  test
This will invoke cvrti for the files with filename=test using painted bounding faces and a single contour line in the mesh. The mesh will also be rotated by 300.0 degrees along the x axis and 350 degrees along the z axis.

BUGS

1. The D command will freeze the screen.

2. There are upper limits on the max number of frames, nodes and triangles.

AUTHOR 

Andrew E. Pollard, Assistant Professor  
Computational Electrophysiology - 536 Boggs  
Tulane University Biomedical Engineering  
New Orleans, LA 70118  
andrew.pollard@tulane.edu