19. The Probability Parameters


Sanding a wood project — it makes a beautiful final finish (even if it takes a lot of work to get there!) A plateaued surface finish is similar to a sanded wood finish: we start with a rough process that creates the valley regions, then we go back over it with a finer process to knock off the peaks and create the plateau. It’s essentially one texture being imposed on another.

In this Notepad Series video we look at the Rq family of surface texture parameters, also known as the “probability parameters,” or “Q” parameters. They describe worn or plateaued surfaces that consist of two distinct distributions of heights. The “Q” parameters are powerful tools for describing the peaks, the valleys, and the position where plateaus meet valleys.