DirectionalLight constructor
color - (optional) hexadecimal color of the light.
Default is 0xffffff.
intensity - (optional) numeric value of the light's
strength/intensity. Default is 1.
Implementation
DirectionalLight([super.color, super.intensity]){
type = "DirectionalLight";
position.setFrom(Object3D.defaultUp);
updateMatrix();
target = Object3D();
shadow = DirectionalLightShadow();
}