There are many user methods performing visualization of objects defined in the applications. Most of them build the scenes from a little basic set of graphical primitives, such as point sets, graphs, or filled polygonal areas. They have a few common attributes controlling their appearance, such as vertex color or line width. The default values for these attributes are chosen by polymake's developers basing on their subjective taste, so you are free to adapt them to your needs.
There are two ways to change the visual attributes. Permanent settings can be stored in your personal customization file ~/.polymake/customize.pl as assignments to custom variables, mostly often in the Visual::Color package. The changes come into effect from the next polymake call and stay until removed manually from the file.
Besides this, almost all visualization methods accept optional attribute_name => value argument pairs, which change the appearance of just the visual objects created by this call. This is especially useful for creating composite drawings with several objects where you might want to distinguish them by different colors. Moreover, you are not constrained by constant values as in the customization file. For many attributes, you can design dynamic mappings and pass them in the form of perl arrays, hash maps, or subroutines. This is described below with more details.
Some attributes have more than one name. For example, a graph node can be referred to as Node or as Vertex, if the graph is in fact the 1-skeleton of a polytope. You can use either name, the effect will be the same.
Please be aware that what follows describes only those attributes that are more or less independent of the visualization software, and can be changed dynamically in the method calls. More software-specific settings can be found in the customization file.
All color settings may be specified either as RGB values with each component being an integer between 0 and 255 (for example, '255 0 0' for red), or using standard symbolic names (for example, "red"). On the most UNIX and Linux systems, the list of recognized color names is kept in the file /usr/X11R6/lib/X11/rgb.txt; if it isn't there, ask your system administrator for assistance and store the location in your customization file.
Normally, a color attribute specifies the filling color of an element. Depending on , the outline can be drawn as a black thin line or left invisible. Some visualization packages, esp. PostScript,
Styles can describe any visual features other than color. The format of the style values is a sequence of keywords, separated with white spaces. The visualization software packages may parse the style values and interpret the parts they can understand, quietly ignoring the rest. Theoretically you can introduce arbitrarily many own style names, provided your favourite visualizer understands them. Below are described only those that make sense with more than one standard visualizer (JavaView, geomview, PostScript.)
There are no default styles, but the visualizers may introduce own default values for some parameters; see the customization file.
The labels are little pieces of text drawn near the vertices, facets, or other graphical elements. Normally, the labels are taken from the corresponding property of the object being visualized, such as VERTEX_LABELS. If the object has no explicit label property, the sequential numbering is taken instead. The only operation you may apply when calling the visualization method is to suppress the labels completely.