SphericalHarmonics.EvaluateSphericalLight Method

Language:

Evaluates a spherical light and returns spectral spherical harmonic (SH) data.

Definition

Visual Basic Public Shared Sub EvaluateSphericalLight( _
    ByVal order As Integer, _
    ByVal position As Vector3, _
    ByVal radius As Single, _
    ByVal redIntensity As Single, _
    ByVal greenIntensity As Single, _
    ByVal blueIntensity As Single, _
    ByVal redOutput As GraphicsStream, _
    ByVal greenOutput As GraphicsStream, _
    ByVal blueOutput As GraphicsStream _
)

C# public static void EvaluateSphericalLight(
    int order,
    Vector3 position,
    float radius,
    float redIntensity,
    float greenIntensity,
    float blueIntensity,
    GraphicsStream redOutput,
    GraphicsStream greenOutput,
    GraphicsStream blueOutput
);

C++ public:
static void EvaluateSphericalLight(
    int order,
    Vector3 position,
    float radius,
    float redIntensity,
    float greenIntensity,
    float blueIntensity,
    GraphicsStream^ redOutput,
    GraphicsStream^ greenOutput,
    GraphicsStream^ blueOutput
);

JScript public static function EvaluateSphericalLight(
    order : int,
    position : Vector3,
    radius : float,
    redIntensity : float,
    greenIntensity : float,
    blueIntensity : float,
    redOutput : GraphicsStream,
    greenOutput : GraphicsStream,
    blueOutput : GraphicsStream
);

Visual Basic	Public Shared Sub EvaluateSphericalLight( _ ByVal order As Integer, _ ByVal position As Vector3, _ ByVal radius As Single, _ ByVal redIntensity As Single, _ ByVal greenIntensity As Single, _ ByVal blueIntensity As Single, _ ByVal redOutput As GraphicsStream, _ ByVal greenOutput As GraphicsStream, _ ByVal blueOutput As GraphicsStream _ )
C#	public static void EvaluateSphericalLight( int order, Vector3 position, float radius, float redIntensity, float greenIntensity, float blueIntensity, GraphicsStream redOutput, GraphicsStream greenOutput, GraphicsStream blueOutput );
C++	public: static void EvaluateSphericalLight( int order, Vector3 position, float radius, float redIntensity, float greenIntensity, float blueIntensity, GraphicsStream^ redOutput, GraphicsStream^ greenOutput, GraphicsStream^ blueOutput );
JScript	public static function EvaluateSphericalLight( order : int, position : Vector3, radius : float, redIntensity : float, greenIntensity : float, blueIntensity : float, redOutput : GraphicsStream, greenOutput : GraphicsStream, blueOutput : GraphicsStream );

Parameters

order System.Int32
Order of the SH evaluation. Must be in the range of SphericalHarmonics.MinimumOrder to SphericalHarmonics.MaximumOrder, inclusive. The evaluation generates order² coefficients. The degree of the evaluation is order - 1.

position Microsoft.DirectX.Vector3
The (x, y, z) hemisphere axis direction vector in which to evaluate the SH basis functions. See Remarks.

radius System.Single
Radius of the spherical light source.

redIntensity System.Single
The red intensity of the light.

greenIntensity System.Single
The green intensity of the light.

blueIntensity System.Single
The blue intensity of the light.

redOutput Microsoft.DirectX.GraphicsStream
Output SH vector for the blue component.

greenOutput Microsoft.DirectX.GraphicsStream
Output SH vector for the green component.

blueOutput Microsoft.DirectX.GraphicsStream
Output SH vector for the blue component.

Remarks

Evaluates a spherical light and returns spectral SH data. There is no normalization of the intensity of the light like there is for directional lights, so care has to be taken when specifying the intensities. This will compute three spectral samples; redOutput will be returned, while greenOutput and blueOutput may be returned.

On the sphere with unit radius as shown, direction can be specified simply with theta, the angle about the z-axis in the right-handed direction, and phi, the angle from z.

The following equations show the relationship between Cartesian (x, y, z) and spherical (theta, phi) coordinates on the unit sphere. The angle theta varies over the range of 0 to 2 pi, while phi varies from 0 to pi.

Exceptions

InvalidCallException The method call is invalid. For example, a method's parameter might contain an invalid value.

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order	System.Int32 Order of the SH evaluation. Must be in the range of SphericalHarmonics.MinimumOrder to SphericalHarmonics.MaximumOrder, inclusive. The evaluation generates order² coefficients. The degree of the evaluation is order - 1.
position	Microsoft.DirectX.Vector3 The (x, y, z) hemisphere axis direction vector in which to evaluate the SH basis functions. See Remarks.
radius	System.Single Radius of the spherical light source.
redIntensity	System.Single The red intensity of the light.
greenIntensity	System.Single The green intensity of the light.
blueIntensity	System.Single The blue intensity of the light.
redOutput	Microsoft.DirectX.GraphicsStream Output SH vector for the blue component.
greenOutput	Microsoft.DirectX.GraphicsStream Output SH vector for the green component.
blueOutput	Microsoft.DirectX.GraphicsStream Output SH vector for the blue component.