Digital Terrain Visualisation
From elevation data to visual experience Overview A mountain exists in the world as stone, ice, gravity, and weather. To render it on a screen, a digital system must first reduce it to numbers — a grid of elevation values, each cell recording how high the earth stands at that point above some reference datum (usually mean sea level). This grid is called a Digital Elevation Model, or DEM. Everything that follows in digital terrain visualisation — the shaded relief, the false-colour palette, the spinning flythrough, the photorealistic render — is a transformation of that grid of numbers into pixels. The mountain you see on Google Earth is not a photograph of a mountain. It is a mathematical surface, coloured and lit by algorithms, viewed through a virtual camera that obeys the same laws of projection as a Renaissance perspectival drawing. Understanding this pipeline — from raw measurement to visual output — is the key to understanding what digital terrain visualisation is, what it inherits, and what it invents. ...