eulerjs API / @eulerjs/marine / SumOfSines

SumOfSines

Defined in: packages/marine/src/waves/SumOfSines.ts:85

An ocean surface made of peaked sinusoids (Acerola's "sum of sines" with exponential waves). Each wave's coordinates are pushed sideways by the slope of the waves before it, which sharpens crests and makes the surface move horizontally, like Gerstner waves.

The surface is a pure function of position and time, so physics and rendering agree as long as both are given the same time.

Constructors

Constructor

new SumOfSines(options?): SumOfSines;

Defined in: packages/marine/src/waves/SumOfSines.ts:109

Parameters

Parameter	Type
options?	SumOfSinesOptions

Returns

SumOfSines

Properties

Property	Modifier	Type	Description	Defined in
fullSamplesPerPeriod	readonly	number	-	packages/marine/src/waves/SumOfSines.ts:93
inversionIterations	readonly	number	-	packages/marine/src/waves/SumOfSines.ts:94
lastGridPoint	readonly	object	Undisplaced grid point found by the last heightAt or heightFrom call.	packages/marine/src/waves/SumOfSines.ts:107
lastGridPoint.x	public	number	-	packages/marine/src/waves/SumOfSines.ts:107
lastGridPoint.z	public	number	-	packages/marine/src/waves/SumOfSines.ts:107
minSamplesPerPeriod	readonly	number	-	packages/marine/src/waves/SumOfSines.ts:92
peakOffset	readonly	number	-	packages/marine/src/waves/SumOfSines.ts:88
peakSharpness	readonly	number	-	packages/marine/src/waves/SumOfSines.ts:87
sampleSpacing	readonly	number	-	packages/marine/src/waves/SumOfSines.ts:91
timeOffset	readonly	number	-	packages/marine/src/waves/SumOfSines.ts:89
timeScale	readonly	number	-	packages/marine/src/waves/SumOfSines.ts:90
waves	readonly	readonly WaveComponent[]	-	packages/marine/src/waves/SumOfSines.ts:86
waveShapeMean	readonly	number	Average of exp(peakSharpness sin(t) - peakOffset) over a period; subtracted so the mean sea level is 0.	packages/marine/src/waves/SumOfSines.ts:96

Methods

heightAt()

heightAt(
   worldX, 
   worldZ, 
   time
): number;

Defined in: packages/marine/src/waves/SumOfSines.ts:171

Height of the surface directly above or below the world position (worldX, worldZ) at time.

Parameters

Parameter	Type
worldX	number
worldZ	number
time	number

Returns

number

---

heightFrom()

heightFrom(
   worldX, 
   worldZ, 
   time, 
   startGridX, 
   startGridZ, 
   iterations
): number;

Defined in: packages/marine/src/waves/SumOfSines.ts:180

Like heightAt, but starts the search for the undisplaced grid point at (startGridX, startGridZ) and runs iterations steps. A good start, such as the answer for the same point a moment ago, needs a single iteration. The grid point found is left in lastGridPoint.

Parameters

Parameter	Type
worldX	number
worldZ	number
time	number
startGridX	number
startGridZ	number
iterations	number

Returns

number

---

normalAt()

normalAt(
   worldX, 
   worldZ, 
   time, 
   target?
): Vector3;

Defined in: packages/marine/src/waves/SumOfSines.ts:197

Upward unit normal of the surface at the world position (worldX, worldZ), by central differences.

Parameters

Parameter	Type
worldX	number
worldZ	number
time	number
target?	Vector3

Returns

Vector3

---

phaseTime()

phaseTime(time): number;

Defined in: packages/marine/src/waves/SumOfSines.ts:140

Time the waves are evaluated at for a given simulation time.

Parameters

Parameter	Type
time	number

Returns

number

---

resolvability()

resolvability(index, spacing): number;

Defined in: packages/marine/src/waves/SumOfSines.ts:148

How much of wave index a grid with this sample spacing can show without aliasing, from 0 (fewer than minSamplesPerPeriod samples per period) to 1 (at least fullSamplesPerPeriod).

Parameters

Parameter	Type
index	number
spacing	number

Returns

number

---

riseRate()

riseRate(
   gridX, 
   gridZ, 
   time
): number;

Defined in: packages/marine/src/waves/SumOfSines.ts:163

Parameters

Parameter	Type
gridX	number
gridZ	number
time	number

Returns

number

---

surfacePoint()

surfacePoint(
   gridX, 
   gridZ, 
   time, 
   target?
): Vector3;

Defined in: packages/marine/src/waves/SumOfSines.ts:157

Where the surface point that started at grid position (gridX, gridZ) is at time. The returned point is displaced sideways as well as vertically.

Parameters

Parameter	Type
gridX	number
gridZ	number
time	number
target?	Vector3

Returns

Vector3