off_color - adds colours to an OFF file

Usage | Examples | Notes

Usage

Description

Read a file in OFF format and add colours to it.

Options

input_file: input file in OFF format, or if not given the program reads from stdin

-h

program help

-v <col>

colour the vertices according to

one integer - colour index for all vertices (0 to clear all colours)
colour value in form r_val,g_val,b_val (values 0.0-1.0, or 0-255) or hex xFFFFFF - colour value for all vertices
u - unique colour using colour indexes
U - unique colour using colour values
p - minimal proper colouring using colour indexes
P - minimal proper colouring using colour values
n - different colour index for each order of vertex
N - different colour for each order of vertex
R[HSVA] - map HSVA values onto the specified HSVA ranges
C[HSV] - gradient on Y coordinate, the gradient can be on the H, S and V range (default: H)
L[HSV] - lighting effect (see option -l) and map HSVA values onto the specified HSVA ranges

-f <col>

colour the faces according to

one integer - colour index for all faces (0 to clear all colours)
colour value in form r_val,g_val,b_val (values 0.0-1.0, or 0-255) or hex xFFFFFF - colour value for all faces
u - unique colour using colour indexes
U - unique colour using colour values
p - minimal proper colouring using colour indexes
P - minimal proper colouring using colour values
n - different colour index for each polygon type (num of sides)
N - different colour for each polygon type (num of sides)
G[HSV] - gradient on Y coordinate of normal, the gradient can be on the H, S and V range (default: H)
C[HSV] - gradient on Y coordinate of centroid, the gradient can be on the H, S and V range (default: H)
R[HSVA] - map HSVA values onto the specified HSVA ranges
L[HSVA] - lighting effect by normal (see option -l) and map HSVA values onto the specified HSVA ranges
l[HSVA] - lighting effect by centroid (see option -l) and map HSVA values onto the specified HSVA ranges

-e <col>

create digons for edges and colour according to

one integer - colour index for all edges (0 for edges without colour)
colour value in form r_val,g_val,b_val (values 0.0-1.0, or 0-255) or hex xFFFFFF - colour value for all edges
u - unique colour using colour indexes
U - unique colour using colour values
p - minimal proper colouring using colour indexes
P - minimal proper colouring using colour values
G[HSV] - gradient on Y coordinate of edge direction, the gradient can be on the H, S and V range (default: H)
C[HSV] - gradient on Y coordinate of centroid, the gradient can be on the H, S and V range (default: H)
R[HSVA] - map HSVA values onto the specified HSVA ranges
L[HSVA] - lighting effect (see option -l) and map HSVA values onto the specified HSVA ranges

-s <sch>

use the colour scheme given by a number (all numbers have a scheme), or if 0 then use a scheme chosen at random

-l <file>

lights for colouring type L in a file in OFF format, each vertex and its colour gives a light direction and colour (default: a set of six lights giving a rainbow colouring

-m <file>

map colour indexes into colour values using colour map file, which contains a list of mappings in the format index_number = colour e.g.

   9 = 0.5 1.0 0.0

with one mapping per line (implies -c which defaults to 2).

-c <conv>

convert indexes after all processing, can be:

1 - use only colours in the colour map file
2 - use colour scheme for index numbers not in the map file

-H <range>

range for hue in generated color map, one or two values, (separated by a comma) between 0.0 and 1.0 (default:0.0,1.0)

-S <range>

range for saturation in generated color map, one or two values, (separated by a comma) between 0.0 and 1.0 (default:0.7,1.0)

-V <range>

range for hue in generated color map, one or two values, (separated by a comma) between 0.0 and 1.0 (default:0.7,1.0)

-o <file>

write output to file, if this option is not used the program writes to standard output

Examples

Make a cuboctahedron with the triangle faces a different colour to the square faces

   unipoly cuboctahedron | off_color -f N -o cubo.off

Same again, but make the colours black and white. Create a file called my_colormap.txt with these two lines which convert index numbers into colour values (with the -f n option faces have an index number the same as their number of sides).

   3 = 0.0 0.0 0.0
   4 = 1.0 1.0 1.0

Now the command is

   unipoly cuboctahedron | off_color -f n -m my_colormap.txt -o cubo.off

Colour faces with unique colours

   geodesic 2 | off_color -f U | antiview -x ve

May a blue-green range for U by specifying a range of the hue

   geodesic 2 | off_color -f U -H 0.4,0.7| antiview -x ve

Make pastel colours for U by decreasing the saturation

   geodesic 2 | off_color -f U -S 0.4| antiview -x ve

Make dark colours for U by decreasing the value

   geodesic 2 | off_color -f U -V 0.4 -S 1| antiview -x ve

Choose from all possible colours for U by giving the full ranges of H, S and V

   geodesic 2 | off_color -f U -H 0,1 -S 0,1 -V 0,1| antiview -x ve

Colour edges and vertices with a rainbow effect

   geodesic 5 | off_color -f 1.0,1.0,1.0 -e L -v L | antiview -v 0.05 -E d

Make a lights file placing a red, green, blue and white light tetrahedrally, call it lts.off

OFF
4 4 0
1 1 1
1 -1 -1
-1 -1 1
-1 1 -1
1 0 255 0 0
1 1 0 255 0
1 2 0 0 255
1 3 255 255 255

Colour faces with a lighting effect using these lights

   geodesic 5 | off_color -l lts.off -f L | antiview -x ve

Notes

Proper colourings are not always optimal

Face colourings G and L which use normals are affected by the orientation of the faces. If the colouring is patchy then orient the faces with off_util -O

A colouring similar to the LiveGraphics3D lights colouring can be acheived with the following lights file (provided by Roger Kaufman.)

OFF
4 4 0
0.86602 -0.61602 0.93301
0.36602 -0.18301 1.68301
-0.5 -0.43301 1.25
-0.36602 0.18301 -1.68301
1 0 1.0 0.0 0.0
1 1 0.0 1.0 0.0
1 2 0.0 0.0 1.0
1 3 1.0 1.0 1.0

Up: Programs and Documentation
Next: off_trans - transformations (rotations etc) of OFF files

Antiprism Documentation 19.6.2007 - http://www.antiprism.com/