Marble Madness
My new map, the Terrain Marble Simulator , allows you to drop a digital marble anywhere in the world and watch it find its way home - or at least to the bottom of the nearest valley. How it Works: Physics in the Browser The simulator is built on MapLibre GL JS , utilizing a custom physics engine that runs in real-time within your browser. When you click the map, the application identifies your coordinates and immediately begins querying the elevation data of the surrounding terrain. By calculating the gradient vector the direction of the steepest descent - the marble is assigned a velocity. We use a method of finite differences to look at the elevation slightly to the north, south, east, and west of the marble to determine which way gravity would pull it. With added momentum and friction variables, the marble doesn't just slide; it rolls, gains speed down cliffs, and orbits around peaks before finally coming to rest in a basin. The Secret Sauce: The Mapterhorn Pipeline The p...
