NLA Editor - duplicating strips

Blender 2.59

I need to duplicate action strips in the NLA Editor to correct some timing issues. So I have a strip that works perfectly in the second half but the first half needs to run faster. An since I have a lot of different keyframes in this strip it next to impossible to move the keyframes individually.

So I can duplicate a strip (no worries, just shift+D) but as soon as I edit the duplicated strip, the changes also affects the original strip - NOT DESIRABLE!

I thought it would help to rename the Active Strip but that doesn’t do the trick.

So how do I make the duplicated strip a truly liberated individual?

Are you editing the strip properties or the action itself?

Both - or neither…? Actually I’m not sure I understand the difference. (The strip is what I see in the NLA-editor contaning the action. The action is what I can see in DopeSheet - or have I misunderstood the concept).

My initial plan was to make a duplicate a strip and then keep only the first keyframes in one strip and the last keyframes in the second strip. Then I would be able to speed up the strip contaning the first keyframes while the pace in the second strip remains untouched.

But any way to receive the same goal is 100% acceptable - as long as I don’t have to edit the keyframes individually

If you make an NLA strip from any Action, any dupes of that strip will be affected by edits to the keyframes in the Action Editor/DopeSheet. The Action determines the “content” of the NLA strip in terms of keyframes.

To Edit the timing of different sections of an NLA strip, you’ll need to make your edits in the NLA Editor, using the tools there, which do not affect the base keyframes directly. For example, make an NLA strip of the entire Action. Then duplicate that, but set the start and end parameters of the duped strip so it covers only a portion of the original Action. Use the Scale parameter to slow this portion down or speed it up. This affects only this particular NLA strip. If you then make a dupe of the first strip (the entire Action) and “trim” it to the remainder of the Action, you can “butt-splice” the two edited strips in the NLA Editor so that the speed of the original Action changes from one portion to the next, but without affecting the keys of the original Action at all.

Obviously it’s a bit more complicated in actuality since you have to edit the NLA strips carefully to make sure your spliced edits flow together smoothly, but that’s the basic methodology. In some cases it might be better to blend the two edited strips over a few frames than use a butt-splice, but that’s all in the details (you know… where the devil lives :wink: )

Thank you chipmasque - this seems very helpful.

So if I understand correctly; the Dopesheet doesn’t really edit the NLA-strip but the Action?

But is there a way to duplicate the Action, then? So I would have my NLA-strips contain seperated Actions (where I can safely delete keyframes without affecting other Actions and then mess with speed on one Action at a time) - because I fear I’ll be very confused and insecure (and most probably annoyed too) juggling speed settings on the same set of keyframes?

In the Action Editor menu bar, next to the name of the Action, is a button with a plus sign ("+"). Clicking this will create a duplicate of the current Action. The dupe Action will have the same name and a numeric suffix like “.001.” etc. You can safely edit keyframes in this copy and not affect those in the original.

If your Action has been linked to more than one object, you’ll also see a button with a number in it, the number of Users that the Action has. Clicking this button will also create a duplicate, a “single-user copy.”

Whenever an NLA strip is duplicated the action associate with the source Strip (say strip A) is also associated with the duplicate strip (say strip B). Now if you try to edit strip B (strip appears green), strip A would show up as red; meaning that strip B has an action which is also associated with strip A. As Chipmasque pointed out, you have to make the action of strip B single user to be able to edit without affecting the action of strip A. This creates a duplicate of the action with a suffix of .001 or more depending on how many duplicates of the actions you create.