toJSON(obj) {
        var json = BaseSerializer.prototype.toJSON.call(this, obj);

        json.antialias = true;
        json.autoClear = obj.autoClear;
        json.autoClearColor = obj.autoClearColor;
        json.autoClearDepth = obj.autoClearDepth;
        json.autoClearStencil = obj.autoClearStencil;
        json.autoUpdateScene = obj.autoUpdateScene;
        json.clippingPlanes = obj.clippingPlanes;
        json.gammaFactor = obj.gammaFactor;
        // json.gammaInput = obj.gammaInput;
        // json.gammaOutput = obj.gammaOutput;
        json.localClippingEnabled = obj.localClippingEnabled;
        json.physicallyCorrectLights = obj.physicallyCorrectLights;
        json.shadowMap = new WebGLShadowMapSerializer().toJSON(obj.shadowMap);
        json.sortObjects = obj.sortObjects;
        json.toneMapping = obj.toneMapping;
        json.toneMappingExposure = obj.toneMappingExposure;
        // json.toneMappingWhitePoint = obj.toneMappingWhitePoint;

        return json;
    }
WebGLRendererSerializer
@author tengge / https://github.com/tengge1