SphericalHarmonics3.html.md 4.2 KB
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
Constructor
new SphericalHarmonics3()
Constructs a new spherical harmonics.
Properties
.coefficients : Array.
An array holding the (9) SH coefficients.
.isSphericalHarmonics3 : boolean (readonly)
This flag can be used for type testing.
Default is true.
Methods
.add( sh : SphericalHarmonics3 ) : SphericalHarmonics3
Adds the given SH to this instance.
sh
The SH to add.
Returns: A reference to this spherical harmonics.
.addScaledSH( sh : SphericalHarmonics3, s : number ) : SphericalHarmonics3
A convenience method for performing SphericalHarmonics3#add and SphericalHarmonics3#scale at once.
sh
The SH to add.
s
The scale factor.
Returns: A reference to this spherical harmonics.
.clone() : SphericalHarmonics3
Returns a new spherical harmonics with copied values from this instance.
Returns: A clone of this instance.
.copy( sh : SphericalHarmonics3 ) : SphericalHarmonics3
Copies the values of the given spherical harmonics to this instance.
sh
The spherical harmonics to copy.
Returns: A reference to this spherical harmonics.
.equals( sh : SphericalHarmonics3 ) : boolean
Returns true if this spherical harmonics is equal with the given one.
sh
The spherical harmonics to test for equality.
Returns: Whether this spherical harmonics is equal with the given one.
.fromArray( array : Array., offset : number ) : SphericalHarmonics3
Sets the SH coefficients of this instance from the given array.
array
An array holding the SH coefficients.
offset
The array offset where to start copying.
Default is 0.
Returns: A clone of this instance.
.getAt( normal : Vector3, target : Vector3 ) : Vector3
Returns the radiance in the direction of the given normal.
normal
The normal vector (assumed to be unit length)
target
The target vector that is used to store the method's result.
Returns: The radiance.
.getIrradianceAt( normal : Vector3, target : Vector3 ) : Vector3
Returns the irradiance (radiance convolved with cosine lobe) in the direction of the given normal.
normal
The normal vector (assumed to be unit length)
target
The target vector that is used to store the method's result.
Returns: The irradiance.
.lerp( sh : SphericalHarmonics3, alpha : number ) : SphericalHarmonics3
Linear interpolates between the given SH and this instance by the given alpha factor.
sh
The SH to interpolate with.
alpha
The alpha factor.
Returns: A reference to this spherical harmonics.
.scale( s : number ) : SphericalHarmonics3
Scales this SH by the given scale factor.
s
The scale factor.
Returns: A reference to this spherical harmonics.
.set( coefficients : Array. ) : SphericalHarmonics3
Sets the given SH coefficients to this instance by copying the values.
coefficients
The SH coefficients.
Returns: A reference to this spherical harmonics.
.toArray( array : Array., offset : number ) : Array.
Returns an array with the SH coefficients, or copies them into the provided array. The coefficients are represented as numbers.
array
The target array.
Default is [].
offset
The array offset where to start copying.
Default is 0.
Returns: An array with flat SH coefficients.
.zero() : SphericalHarmonics3
Sets all SH coefficients to 0.
Returns: A reference to this spherical harmonics.
Static Methods
.getBasisAt( normal : Vector3, shBasis : Array. )
Computes the SH basis for the given normal vector.
normal
The normal.
shBasis
The target array holding the SH basis.