How to Undo a lot of created objects at once? [Solved]

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Hello everybody and good day.

I have a little problem trying to make an Undo step after creating a bunch of objects using a for loop method (in edit not play), I read the docs about it but honestly I don’t understand how that could be done or even if that it’s possible.

I know that undo a group of selected objects can be done after deletion but not at creation, so, any one could help me to resolve this?, I’m not an experienced programmer, but I can understand many things about coding inside Unity (except this one about Undo group things).

1 Answer

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After some API study, I found the solution by my self.
In the 2018.x version, to make an undo of more than 1 object, only have to do this:

Undo.RecordObject(null, "Base Undo");
int undoID = Undo.GetCurrentGroup();
//Sample---
for (int i = 0; i < 10; i++){
    GameObject go = Instantiate(original);
    Undo.RegisterCreatedObjectUndo(go, "New Undo");
    Undo.CollapseUndoOperations(undoID);
}

With this, can be undone many objects at once.

In version 2018.4.13f1 when this line is executed Undo.RecordObject(null, "Base Undo"); I get this error Undo object may not be null. Also you're using Undo.CollapseUndoOperations(undoID) every time you create a new object. I think this the correct way Undo.IncrementCurrentGroup(); Undo.SetCurrentGroupName("Undo name"); var undoGroupIndex = Undo.GetCurrentGroup(); for (int i = 0; i < 10; i++) { GameObject go = Instantiate(original); Undo.RegisterCreatedObjectUndo(go, ""); } Undo.CollapseUndoOperations(undoGroupIndex);

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