toJson method
meta - object containing metadata such as materials, textures for
objects.
Convert the light to three.js JSON Object/Scene format.
Implementation
@override
Map<String, dynamic> toJson({Object3dMeta? meta}) {
  Map<String, dynamic> data = super.toJson(meta: meta);
  data["object"]["color"] = color!.getHex();
  data["object"]["intensity"] = intensity;
  if (groundColor != null) {
    data["object"]["groundColor"] = groundColor!.getHex();
  }
  if (distance != null) {
    data["object"]["distance"] = distance;
  }
  if (angle != null) {
    data["object"]["angle"] = angle;
  }
  if (decay != null) {
    data["object"]["decay"] = decay;
  }
  if (penumbra != null) {
    data["object"]["penumbra"] = penumbra;
  }
  if (shadow != null) {
    data["object"]["shadow"] = shadow!.toJson();
  }
  return data;
}