A misplaced drag, an accidental edit, or a construction step that takes a model in the wrong direction can interrupt careful molecular work. The key is knowing what SAMSON’s history can help you recover—and where its limits are.
Every SAMSON document has its own history: a list of undoable actions performed in that document. You can use it to move through earlier document states, rather than relying only on repeated keyboard shortcuts. This is useful when you know the model looked right a few steps ago but are unsure exactly which action caused the problem.
Open history before you need it
Open the History view from Interface > History, or use Ctrl+3 on Windows and Linux, and Cmd+3 on Mac. Keeping the history view available while you edit, build, or move structures makes it easier to see the sequence of recorded actions and return to an earlier state.
You can navigate through document states by clicking actions in the History view. For a quick reversal, use Edit > Undo or the shortcut Ctrl+Z on Windows and Linux, or Cmd+Z on Mac. To move forward again, choose Edit > Redo, or press Ctrl+Y on Windows and Linux, or Cmd+Y on Mac.
A practical recovery routine
- Pause when the structure looks wrong. Avoid making extra edits before checking the history; additional actions can make it harder to identify the change you want to reverse.
- Inspect the recent actions. Use the History view to review the recorded sequence and locate a state that matches the model you want to return to.
- Move back carefully. Click an earlier action in the history, or use Undo step by step. Check the document after moving back so you can confirm that the structure is in the intended state.
- Redo if you went too far. Redo moves forward through the history, which can help you restore an action you just reversed.
This approach is especially useful while testing transformations or constructing and editing structures: it encourages small, reviewable steps instead of trying to reconstruct a previous arrangement from memory. The history is tied to a document, so if you are working with more than one document, make sure you are inspecting the history for the one you intend to change.
Know the important limitation
Not every operation is undoable. The documentation cautions that if non-undoable operations occur between undoable ones, SAMSON may not be able to undo the sequence properly, and data loss may result. Undo and redo are therefore helpful recovery tools, but they are not a guarantee that every operation can be reversed. Before a sequence of consequential edits, consider saving your work using your usual file workflow; do not rely on history alone as a backup.
The History view can make recovery more deliberate: review what happened, return to a suitable earlier state, and verify the result before continuing. See the SAMSON History documentation for more details.
Note: SAMSON and all SAMSON Extensions are free for non-commercial use. Get SAMSON.