You can override the default error handler by specifying a callback function to be invoked when an error is posted. Each subclass of SoError SoError SoError supports a static setHandlerCallback() method. You can register the callback on SoError SoError SoError , so that it is called for all errors, or you can register it on one of the classes derived from SoError SoError SoError . The callback for the most derived class of a specific error instance is used to handle the error. Note that the error instance passed to a callback is deleted immediately after the callback is invoked. The application must copy this data ahead of time if it needs to use it later.