# PaintSurface

NAME

    PaintSurface - set coloring style of surfaces

SYNOPSIS

    PaintSurface ( one_color | atom | dist | center |
        access | pot ) expr expr expr expr string

DESCRIPTION

Set the coloring style of all selected surfaces. With the value one_color, the surface will be drawn entirely in the color set with `ColorPrim`.

With the value atom, the color for each point is taken from the color of the closest selected atom. For this case, the third argument gives the maximum distance from the atom surface, the user will normally give the solvent radius used for calculating the surface for this argument.

With the value dist, the color for each point is calculated from the smallest distance to a selected atom, using the mapping of values to colors described below.

With the value center, the color for each point is calculated from the distance to the center of gravity of all selected atoms, using the mapping of values to colors described below.

With the value access, the color for each point is calculated from the accessibility of the point, using the mapping of values to colors described below. The accessibility is calculated by an experimental (and relatively slow) algorithm that casts a number (4**p, where p is the precision given as fifth argument) of rays from each surface point, and counts how many of them intersect a selected atom within the distance range given by the second and third argument. A small offset given as fourth argument is normally applied to each surface point to avoid artefacts.

With the value pot, the color is calculated from a potential field read with `ReadPot`, using the mapping of values to colors described below.

For the options that require a mapping of values to colors, this mapping is given by the last argument. It consists of space separated tuples of the form:

        v r g b

where v is the potential and r, g, b give the color as RGB (red, green, blue) components. Colors are interpolated between the values in the table.

Potentials have to be calculated with the `CalcPot` command, and then read with `ReadPot`, before using this command with the corresponding option.

EXAMPLE

    PaintSurface atom 0.0 1.4 0.0 0 ''
    PaintSurface dist 0.0 0.0 0.0 0
        '5.0 1 0 0 10.0 1 0 1 20.0 0 0 1'
    PaintSurface access 3.0 8.0 0.2 2
        '0.4 1 0 0 0.5 1 1 0 0.8 0 1 0'
    PaintSurface pot 0.0 0.0 0.0 0.0 '0.0 0 0 1 4.0 1 0 0'

SEE ALSO

`AddSurface`, `SelectPrim`, `CalcPot`, `ReadPot`, `ColorPrim`, `ColorAtom`

DATE

991031