Undo Related To Python Scripting

[Atom]

Hi All,

I have two python nodes. The first python node programs the parameters on a second python node. The second python node reads the parameters and alters bones. This seems to work fine, I scrub my animation and my rig changes.

There are also parameters on the second node that I am manually keyframing.

I have started to notice that when I am manually keyframing that second python node and I scrub back and forth then decide to issue an Undo on my manual keyframe that Houdini has lost my last input and never does the undo no matter how many times I press CTRL-Z.

At first I thought this might be a bug then I wondered if Houdini may be undoing my other scripts changes to the parameters that it just set?

Could my first nodes manipulation of the second nodes parameters be affecting the undo stack?

In other app I have programmed, After Effects, Blender etc.. there was a mechanism to essentially lock an undo while some code ran, then restoring the undo so the entire operation that happened inside the lock was considered a single undo item on the stack, this way if my code changes 100 items, issuing a manual undo will undo those 100 items, not just item #100, #99 and so on.

Does Houdini have such a mechanism in it's Python implementation?

Thanks

[holycause]

Looking at the documentation, there is an hou.undos module

https://www.sidefx.com/docs/houdini/hom/hou/undos

[Atom]

Thanks, I'll give that a try.