Colors and Color Maps

In COMPAS colors are defined in RGB color space, with components in the range of 0-1.

Basic Usage

Color Spaces

Color Information

The RGB Color Circle

The color class (compas.colors.Color) provides constructor methods for the primary, secondary, and tertiary colors of the RGB color wheel or color circle.

Primary Colors

>>> Color.red()
Color(1.0, 0.0, 0.0, 1.0)
>>> Color.green()
Color(0.0, 1.0, 0.0, 1.0)
>>> Color.blue()
Color(0.0, 0.0, 1.0, 1.0)

Secondary Colors

>>> Color.yellow()
Color(1.0, 1.0, 0.0, 1.0)
>>> Color.cyan()
Color(0.0, 1.0, 1.0, 1.0)
>>> Color.magenta()
Color(1.0, 0.0, 1.0, 1.0)

Tertiary Colors

>>> Color.orange()
Color(1.0, 0.5, 0.0, 1.0)
>>> Color.lime()
Color(0.5, 1.0, 0.0, 1.0)
>>> Color.mint()
Color(0.0, 1.0, 0.5, 1.0)
>>> Color.azure()
Color(0.0, 0.5, 1.0, 1.0)
>>> Color.violet()
Color(0.5, 0.0, 1.0, 1.0)
>>> Color.pink()
Color(1.0, 0.0, 0.5, 1.0)

../_images/basics.colors_color-circle.png — The RGB color circle.

Lighter and Darker Colors

The color class (compas.colors.Color) provides methods to generate lighter and darker variations of a given color. The methods can be used to modify the colors in-place (compas.colors.Color.lighten() and compas.colors.Color.darken()), or to generate new colors (compas.colors.Color.lightened() and compas.colors.Color.darkened()).

>>> red = Color.red()
>>> red.lighten(50)
None
>>> red.darken(50)
None
>>> red
Color(1.0, 0.0, 0.0, 1.0)

>>> red = Color.red()
>>> red.lightened(50)
Color(1.0, 0.5, 0.5, 1.0)
>>> red.darkened(50)
Color(0.5, 0.0, 0.0, 1.0)

../_images/basics.colors_lightness.png — Lightness.

Saturation

Similar to generating lighter and darker colors, the color class provides methods for saturating or desaturating colors (compas.colors.Color.saturate() and compas.colors.Color.desaturate(), and compas.colors.Color.saturated() and compas.colors.Color.desaturated()).

Color Maps

Using compas.colors.ColorMap, color maps can be constructed from various color inputs.

Maps based on named scientific color palettes designed by Fabio Crameri (https://www.fabiocrameri.ch/colourmaps/) and some of the matplotlib color palettes are also available.

There is currently no predefined function for color map examples. However, using the following template we can compare various examples.

>>> from compas.geometry import Point, Polygon
>>> from compas.utilities import linspace, pairwise
>>> from compas.datastructures import Mesh
>>> from compas.colors import Color, ColorMap
>>> from compas_view2.app import App

>>> n = 1000
>>> t = 0.3

>>> up = []
>>> down = []
>>> for i in linspace(0, 10, n):
...    point = Point(i, 0, 0)
...    up.append(point + [0, t, 0])
...    down.append(point - [0, t, 0])

>>> polygons = []
>>> for (d, c), (a, b) in zip(pairwise(up), pairwise(down)):
...    polygons.append(Polygon([a, b, c, d]))

>>> mesh = Mesh.from_polygons(polygons)

>>> cmap = ...  # define color map here
>>> facecolors = {i: cmap(i, minval=0, maxval=n - 1) for i in range(n)}

>>> viewer = App()
>>> viewer.view.show_grid = False
>>> viewer.add(mesh, facecolor=facecolors, show_lines=False)
>>> viewer.show()

From Palette

>>> cmap = ColorMap.from_mpl('viridis')

../_images/basics.colors_maps.png — viridis color map from matplotlib.

From RGB

>>> cmap = ColorMap.from_rgb()

From One Color

>>> cmap = ColorMap.from_color(Color.red())
>>> cmap = ColorMap.from_color(Color.red(), rangetype='light')
>>> cmap = ColorMap.from_color(Color.red(), rangetype='dark')

From Two Colors

>>> cmap = ColorMap.from_two_colors(Color.from_hex('#0092D2'), Color.pink())
>>> cmap = ColorMap.from_two_colors(Color.from_hex('#0092D2'), Color.pink(), diverging=True)

From Three Colors

>>> cmap = ColorMap.from_three_colors(Color.red(), Color.green(), Color.blue())