Properties for managing image-based lighting on tilesets and models.
Also manages the necessary resources and textures.
If specular environment maps are used, ImageBasedLighting#destroy must be called
when the image-based lighting is no longer needed to clean up GPU resources properly.
If a model or tileset creates an instance of ImageBasedLighting, it will handle this.
Otherwise, the application is responsible for calling destroy().
| Name | Type | Default | Description |
|---|---|---|---|
options.imageBasedLightingFactor |
Cartesian2 |
Cartesian2(1.0, 1.0)
|
optional Scales diffuse and specular image-based lighting from the earth, sky, atmosphere and star skybox. |
options.luminanceAtZenith |
number |
0.2
|
optional The sun's luminance at the zenith in kilo candela per meter squared to use for this model's procedural environment map. |
options.sphericalHarmonicCoefficients |
Array.<Cartesian3> | optional The third order spherical harmonic coefficients used for the diffuse color of image-based lighting. | |
options.specularEnvironmentMaps |
string | optional A URL to a KTX2 file that contains a cube map of the specular lighting and the convoluted specular mipmaps. |
Members
imageBasedLightingFactor : Cartesian2
Cesium adds lighting from the earth, sky, atmosphere, and star skybox.
This cartesian is used to scale the final diffuse and specular lighting
contribution from those sources to the final color. A value of 0.0 will
disable those light sources.
-
Default Value:
Cartesian2(1.0, 1.0)
The sun's luminance at the zenith in kilo candela per meter squared
to use for this model's procedural environment map. This is used when
ImageBasedLighting#specularEnvironmentMaps and ImageBasedLighting#sphericalHarmonicCoefficients
are not defined.
-
Default Value:
0.2
A URL to a KTX2 file that contains a cube map of the specular lighting and the convoluted specular mipmaps.
sphericalHarmonicCoefficients : Array.<Cartesian3>
The third order spherical harmonic coefficients used for the diffuse color of image-based lighting. When
undefined, a diffuse irradiance
computed from the atmosphere color is used.
There are nine Cartesian3 coefficients.
The order of the coefficients is: L0,0, L1,-1, L1,0, L1,1, L2,-2, L2,-1, L2,0, L2,1, L2,2
cmgen tool of
Google's Filament project. This will also generate a KTX file that can be
supplied to Model#specularEnvironmentMaps.