raisin::WaterWaveSpectrum

struct · #include <rayrai/Water.hpp>

Parameters of generateGerstnerWaves(): a wind-driven set of waves, long to short.

Wave i of n gets the rank a = 1 - i / n, jittered by randomness / n. Its wavelength is mix(minWavelength, maxWavelength, a^wavelengthFalloff), its amplitude mix(minAmplitude, maxAmplitude, a^amplitudeFalloff) and its steepness mix(longWaveSteepness, shortWaveSteepness, (i / n)^steepnessFalloff), scaled down together when they add up to more than maxSteepnessSum. Wave 0 travels along the wind; the others are turned by a random angle within +-directionSpreadRadians.

Public attributes

waveCount

int waveCount

Number of waves, [1, kMaxWaterWaves].

seed

uint32_t seed

Seed of the directions, the jitter and the phases.

windAngleRadians

float windAngleRadians

Dominant travel direction, radians from +X toward +Y.

directionSpreadRadians

float directionSpreadRadians

Half range of the direction offsets, [0, pi].

minWavelength

float minWavelength

Shortest wave, metres (> 0).

maxWavelength

float maxWavelength

Longest wave, metres (>= minWavelength).

wavelengthFalloff

float wavelengthFalloff

Rank exponent of the wavelength (> 0); larger values give more short waves.

minAmplitude

float minAmplitude

Amplitude of the shortest wave, metres (>= 0).

maxAmplitude

float maxAmplitude

Amplitude of the longest wave, metres (>= minAmplitude).

amplitudeFalloff

float amplitudeFalloff

Rank exponent of the amplitude (> 0).

longWaveSteepness

float longWaveSteepness

Steepness of the longest wave, [0, 1].

shortWaveSteepness

float shortWaveSteepness

Steepness of the shortest wave, [0, 1].

steepnessFalloff

float steepnessFalloff

Rank exponent of the steepness (> 0).

randomness

float randomness

Rank jitter, [0, 1].

maxSteepnessSum

float maxSteepnessSum

Upper bound of the summed steepness, [0, 1]; the steepness of every wave is scaled down to meet it. A sum up to 1 never folds the surface over.