Currently, the Undo/Redo stack in the Creo Parametric session seems to be cleared when calling any Creo Parametric TOOLKIT functions and this specification causes inconvenience or even barrier for users of a Creo Parametric TOOLKIT application depending on the usage of TOOLKIT APIs.
There is a note in a Creo Parametric TOOLKIT User's Guide as below:
All Creo Parametric TOOLKIT calls running in either synchronous (DLL or multiprocess) mode or asynchronous mode always clear the Undo/Redo stack in the Creo Parametric session. The Creo Parametric user interface reflects this by making the Undo and Redo menu options unavailable.
In one of Creo Parametric applications using TOOLKIT APIs, we are creating a thread to capture model view matrix using ProViewMatixGet() at regular time intervals in order to synchronize model view with other CAD application. In such usage, users can not use undo/redo for any operations done in Creo Parametric due to this specification.
So we would like to submit an enhancement request to provide a way not to clear the Undo/Redo stack when calling Creo Parametric TOOLKIT APIs.