This repository contains a working implementation of Kubelka-Munk theory, but with fake K/S data. This being released as an educational guide, and to help those interested in developing their own imaginary pigments.
Kubelka-Munk theory models the color of a mixture of pigments. To do so, it uses information about the pigments in the form of their K (absorption) and S (scattering) curves. These curves relate wavelengths of light (typically in the visible spectrum) to the amount of light absorped or scattered.
Kubelka-Munk theory is both effective and efficient when it comes to simulating pigment mixtures. However, it is difficult to acquire the needed K & S curves to perform this mixing accurately. Doing so by hand requires a lot of careful data collection and computation (see this thesis for more information). In addition, the K & S curves are considered to be the IP of the paint manufacturer, so they are not keen to have them shared once known.
This repository contains an implementation of Kubelka-Munk pigment mixing, but
with fake spectral data for the supplied WHITE, BLUE, and YELLOW
pigments. These fake spectral curves look like this:
These approxmiate white, yellow, and blue, but when mixed still create grey:
To perform more interesting or convincing mixing, better spectral data is needed. Feel free to contribute improved K/S curves if you develop them. Do not contribute curves that may be considered IP.
You can demo the pigment mixing in your browser. For convenience sake, the
serve script runs a Python HTTP server in this directory:
$ ./serve
$ # open http://localhost:9119 in your browserTry changing the colors (or adding more) in consts.js. These are interpreted
and mixed in the fragment shader in km.js.
- Spectral data source: https://cie.co.at/data-tables.
- Overview of KM mixing: https://scholarworks.rit.edu/theses/4892/