Terrain

about

Terrain is an instrument whose timbre is topography. Draw a rectangle on the map and the elevation inside it is sampled on a grid; each west-to-east row of samples is a single-cycle waveform, the rows stack into a wavetable, and Position sweeps south to north through the stack. Fly the landscape and the flight does the sweeping. It is free and open, and it began as a native Audio Unit and VST3 built on JUCE.

Elevation — Terrain Tiles on the AWS Open Data registry (Mapzen / Tilezen), a global blend of SRTM, GMTED2010, ETOPO1 bathymetry, EU-DEM, and USGS 3DEP. Source attribution at tilezen/joerd. The sea floor is data too.

Coastlines — Natural Earth (public domain), 1:110m.

Search — Photon by komoot, data © OpenStreetMap contributors (ODbL).

Plain HTML, canvas, and Web Audio (an AudioWorklet wavetable synth); no libraries.

region

lat lon

span lat span lon

lat samples32 lon samples24

sweep

position y0.00 position x0.00 mix rows ↔ columns0.50

directionS → N · W → E

lfo rate0.20 Hz x rate×1.00 lfo depth1.00 cruise0.50

voice

reading tilt0 dB/oct unison2 detune10 ct spread0.60

filter

cutoff6.0 kHz resonance0.15 envelope0.40 key track0.50

envelope

attack0.01 s decay0.20 s sustain0.80 release0.30 s

space

pan by east–west1.00 reverb0.25 room2.5 s gain0.80

idle

hold the mouse to fly, steer by where the cursor sits · middle-drag to orbit, shift+middle or right-drag to pan, wheel to zoom toward the cursor, double middle-click or shift+z to frame the region · flying takes both sweeps from the lfo · rows sweep south to north, columns west to east, mixed by the slider · drag a box on the map, or drag its centre · play the keys, or a–k on the keyboard, or a MIDI keyboard