Color Maps
Built-in color maps
Different color maps are appropriate for different situations:
- sequential maps data in to a linear range (when it doesn’t fall in to one of the more specific categories below).
- diverging maps data in to a linear range, where the center value is “neutral” and the endpoints of the range are opposite and symmetric. Examples include a rate of change, or a residual; in both cases
0semantially means “nothing”, and the endpoints have opposite meaning. - cyclic maps data defined on the circle, like an angle
- decorative maps should generally not be used to encode numerical data, but may be useful for other visualization purposes
Polyscope supports the following built-in color maps:
| Name | Type | String Key |
|---|---|---|
| viridis | sequential | viridis |
| blues | sequential | blues |
| reds | sequential | reds |
| coolwarm | diverging | coolwarm |
| pink-green | diverging | pink-green |
| phase | cyclic | phase |
| spectral | decorative | spectral |
| rainbow | decorative | rainbow |
| jet | decorative | jet |
| turbo | decorative | turbo |
Loading custom color maps
Custom colormaps can be loaded at runtime from image files and used anywhere colormaps are used. Loading can be performed with the UI from [Appearance] --> [Color maps] --> [Load color map], or programatically using the function below. The input should be a horizontally-oriented image file like the one below; the centermost row of pixels will be read to generate the color map. Most common image formats are accepted (anyting stb_image can read).
void polyscope::loadColorMap(std::string cmapName, std::string filename)
loadColorMap
Load a new colormap from the image file filename, which will be assigned the name cmapName.