function SpecularGlossiness() {
  /**
   * The diffuse texture reader.
   *
   * @type {ModelComponents.TextureReader}
   * @private
   */
  this.diffuseTexture = undefined;

  /**
   * The specular glossiness texture reader.
   *
   * @type {ModelComponents.TextureReader}
   * @private
   */
  this.specularGlossinessTexture = undefined;

  /**
   * The diffuse factor.
   *
   * @type {Cartesian4}
   * @default new Cartesian4(1.0, 1.0, 1.0, 1.0)
   * @private
   */
  this.diffuseFactor = Cartesian4.clone(
    SpecularGlossiness.DEFAULT_DIFFUSE_FACTOR,
  );

  /**
   * The specular factor.
   *
   * @type {Cartesian3}
   * @default new Cartesian3(1.0, 1.0, 1.0)
   * @private
   */
  this.specularFactor = Cartesian3.clone(
    SpecularGlossiness.DEFAULT_SPECULAR_FACTOR,
  );

  /**
   * The glossiness factor.
   *
   * @type {number}
   * @default 1.0
   * @private
   */
  this.glossinessFactor = SpecularGlossiness.DEFAULT_GLOSSINESS_FACTOR;
}
Material properties for the PBR specular glossiness shading model.

@alias ModelComponents.SpecularGlossiness
@constructor

@private