Color Maps

Image files

It is possible to specify a color map using the --colormap-file option. The value of the option can be an absolute path to an image file, a relative path, a filename or a filestem. If it is not an absolute path, these directories are used to find the file (in this order):

• Linux: ${XDG_CONFIG_HOME}/f3d/colormaps, ~/.config/f3d/colormaps, /etc/f3d/colormaps, /usr/share/f3d/colormaps, [install_dir]/share/f3d/colormaps
• Windows: %APPDATA%\f3d\colormaps, [install_dir]\share\f3d\configs\colormaps
• macOS: ${XDG_CONFIG_HOME}/f3d/colormaps, ~/.config/f3d/colormaps, /usr/local/etc/f3d/colormaps, f3d.app/Contents/Resources/configs/colormaps The first existing file found is used. If it is a filestem, all supported image extensions are tried.

We provide some ready to use color maps files, listed in the table below:

Name	Image
cividis
cubehelix
gist_earth
hot
inferno
magma
plasma
seismic
viridis

It is possible to create a custom color map by creating a simple RGB image in any supported formats, and any resolution (if the height is more than 1 row, only the first one is taken into account). The image must be copied in the user config directory:

• Linux/macOS: ~/.config/f3d/colormaps
• Windows: %APPDATA%\f3d\colormaps

Supported formats

Here's the list of all supported image formats that can be used as color maps:

• .png
• .pnm, .pgm, .ppm
• .tif, .tiff
• .bmp
• .slc
• .hdr
• .pic
• .jpeg, .jpg
• .MR
• .CT
• .mhd, .mha
• .tga
• .exr (if F3D_MODULE_EXR is enabled)
• .webp (if F3D_MODULE_WEBP is enabled)

Custom values

If no colormap file is specified, it is also possible to set values manually using the --colormap option with a dedicated parsing. For example, the default value corresponds to the hot preset which can be defined manually with --colormap=0.0,rgb(0,0,0),0.4,rgb(230,0,0),0.8,rgb(230,230,0),1.0,rgb(255,255,255). It consists of 4 pairs of increasing scalar values ranging from 0 to 1, and corresponding colors. Values in between are interpolated.