Hi Pilou, Undos are already automatically purged if they start to take up too much space.

The way the undo system works it will for sure save at least 10 steps, and then it will save as many more than that as possible until they take up more than 20MB of memory. At that point the oldest undo records will be discarded.

These settings can be changed in the moi.ini file here:

[Undo]
MaxMemorySizeMB=20
MinNumberOfUndos=10

But even if you don't have much memory 20MB is not really very much so I don't really recommend messing with those settings.


One thing that can help if you have a limited amount of memory or if even if you have a lot of memory and you're working on very large files is to adjust the display mesh density to use a coarser mesh, see here for some info on that:
http://moi3d.com/forum/index.php?webtag=MOI&msg=4196.2

- Michael