function getMaterialData(data, materialData) {
  materialData.color.set(data.color);
  materialData.fog = data.fog;
  materialData.wireframe = data.wireframe;
  materialData.toneMapped = data.toneMapped;
  materialData.wireframeLinewidth = data.wireframeLinewidth;
  return materialData;
}
Builds and normalize material data, normalizing stuff along the way.

@param {object} data - Material data.
@param {object} materialData - Object to reuse.
@returns {object} Updated material data.