@Override
    public void write(Json json) {
        json.writeValue("atlasData", atlasData);
        json.writeValue("jsonData", jsonData);
        json.writeValue("preferences", preferences);
        if (saveFile != null) {
            json.writeValue("saveFile", saveFile.path());
        } else {
            json.writeValue("saveFile", (String) null);
        }
        json.writeValue("version", Main.VERSION);
        json.writeValue("sceneComposer", DialogSceneComposerModel.rootActor);
    }
Checks every drawable path for existence. Errors are reported as a list
of DrawableDatas.
@return A list of all DrawableDatas that must have their paths resolved.
Returns an empty list if there are no errors.
core/src/com/ray3k/skincomposer/data/ProjectData.java