kite3d/io.github.yuroyami.kite3d.math/SphericalHarmonics3

SphericalHarmonics3

class SphericalHarmonics3

Represents a third-order spherical harmonics (SH). Light probes use this class to encode lighting information.

Primary reference: https://graphics.stanford.edu/papers/envmap/envmap.pdf
Secondary reference: https://www.ppsloan.org/publications/StupidSH36.pdf

Instances are mutable and not thread-safe; confine an instance to a single thread, exactly as in three.js.

The isSphericalHarmonics3 duck-typing flag is intentionally dropped. Use is SphericalHarmonics3 instead.

Constructors

SphericalHarmonics3

constructor()

Types

Companion

object Companion

Properties

coefficients

val coefficients: Array<Vector3>

An array holding the (9) SH coefficients.

Functions

add

fun add(sh: SphericalHarmonics3): SphericalHarmonics3

Adds the given SH to this instance.

addScaledSH

fun addScaledSH(sh: SphericalHarmonics3, s: Double): SphericalHarmonics3

A convenience method for performing add and scale at once.

clone

fun clone(): SphericalHarmonics3

Returns a new spherical harmonics with copied values from this instance.

copy

fun copy(sh: SphericalHarmonics3): SphericalHarmonics3

Copies the values of the given spherical harmonics to this instance.

equals

open operator override fun equals(other: Any?): Boolean

Structural equality: true when other is a SphericalHarmonics3 whose nine coefficients are all equal (via Vector3.equals, so NaN != NaN).

fromArray

fun fromArray(array: DoubleArray, offset: Int = 0): SphericalHarmonics3

Sets the SH coefficients of this instance from the given array.

getAt

fun getAt(normal: Vector3, target: Vector3): Vector3

Returns the radiance in the direction of the given normal.

getIrradianceAt

fun getIrradianceAt(normal: Vector3, target: Vector3): Vector3

Returns the irradiance (radiance convolved with cosine lobe) in the direction of the given normal.

hashCode

open override fun hashCode(): Int

lerp

fun lerp(sh: SphericalHarmonics3, alpha: Double): SphericalHarmonics3

Linear interpolates between the given SH and this instance by the given alpha factor.

scale

fun scale(s: Double): SphericalHarmonics3

Scales this SH by the given scale factor.

set

fun set(coefficients: Array<Vector3>): SphericalHarmonics3

Sets the given SH coefficients to this instance by copying the values.

toArray

fun toArray(array: MutableList<Double> = mutableListOf(), offset: Int = 0): MutableList<Double>

Returns an array with the SH coefficients, or copies them into the provided array. The coefficients are represented as numbers.

toString

open override fun toString(): String

zero

fun zero(): SphericalHarmonics3

Sets all SH coefficients to 0.