tutorials on creating, transitioning actions?

Support Animation and Rigging
#1

Okay, the Noob to Pro wiki book is still not up to snuff on the animation pages. I know how to pose my rigged character, and I know how basic keyframe IPO animation works, but I am having a hard time getting to understand the idea of Actions and the NLA editor.

Is there a tutorial out there which is for 2.40 and the best way to (1) make your first action, (2) make a completely different action, and (3) combine them? There are walkcycle tutorials coming out my ears, but none of them really go to the next step (so to speak).

My goal project is to animate martial arts moves. In training, one kinda learns “keyframe” poses, and incorporates them into moves (kata or waza). More complicated motions are just built from smaller components.

#2

It’s quite easy and maybe that’s why there’s no specific tut. Let’s say you want to make two actions, AC:Hit and AC:Kick. Start with poseing Hit and an Action will automatically be created in the Action Editor consisting of all the Bones that use Action IPO’s. That’s done so return to Frame 1 which will be your default Stance of AC:Hit.

Now, in the Action Editor, click the X (delete) next to AC:Hit and the datablock menu will disappear. (If you Add New instead of deleting then it will copy selected bones to the new action and you don’t always want that). If you want a new default pose for AC:Kick, then Pose it or the same stance will be used as was the default in AC:Hit. Pose and Keyframe your Kick action and name it.

Over in the NLA Editor you can now use Shft-A to add NLA-Strips of your Actions, Grab and Scale them and use the Transform Properties tab to input how they Blend.

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#3

Thanks for the walkthrough. I’ll try it with a two-bone dummy for a bit to get used to it. I do think it’s worth some mention somewhere, since it’s an important workflow and not everyone’s used Max or Maya for years.

You didn’t specify how or where these AC: get their names, etc., or how an action knows its length in frames. I guess it will become more obvious as I go.

#4

/giggle… I’ve only ever opened Blender, know nothing about other apps.

You didn’t specify how or where these AC:

In the Action Editor’s header, in the Action Menu where it says AC:Action, click on it so the Action part goes red and type in the new name. That will be carried over to the NLA Editor too.

or how an action knows its length in frames.

By default it is as many frames as there exist between the first and last KeyFrame. In the NLA Editor you can use the Transform Properties tab (N) to (re)set both the length of the Action and the length of the Strip.

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#5

Okay, I finally found the things you were talking about, but they’re far from obvious.

(1) the NLA Editor does not list Shift+A anywhere to add another track, you just have to magically know that keystroke?

(2) the NLA Editor will respond with the poorly worded “Error: Object has not an Action” if you haven’t clicked on the armature name in question.

(3) if you click on the armature name, it does not visually change anything. You can’t tell that suddenly it’s armed and ready for that secret Shift+A keystroke to get the popup menu.

(4) it’s still very unsettling to design an action in the Action Editor, then trust that the automatically-applied F (fake user) flag will keep the action from getting deleted while you work on other actions. Only the currently selected action seems to appear in the Outliner view, too, making it even more unsettling. If the Outliner showed an Action icon entry for every Action you’ve made, whether it’s currently being edited or not, it would go a lot farther toward trusting that I’m not deleting or dis-referencing something, and showing other people what an armature was designed to do.

I’ll be sharing this feedback with the #blendercoders too.

Thanks for your help!

#6

I created a three-bone noodly thing as a test.

I created an AC:Boing, where it starts standing on one end, and jumps up and lands.

I created an AC:Topple, where it starts standing on one end, and falls to the side.

In the NLA, I have added multiple channels, hoping to Boing three times then Topple. I moved the rectangular tapes to go through that sequence over the course of 50 frames.

But it still only plays one active action at a time when I sweep the current frame or hit Alt+A. It ignores the added tracks, except in that I can click those to set which action is active.

What do I do next to get it to actually build the animation I want?

#7

If you select an Action, at first its name will appear in the NLA window along with its keys. To make a strip, point at the Action’s name in the NLA and do Ctrl-C to convert the action to a strip.

Close any open Actions by clicking the scary X in the Action Editor. If you don’t do this, only this action will play. Now in the NLA editor, select all your strips by pressing ‘A’ until they all turn yellow (just like mesh editing), and play the animation.

EDIT: I was wrong; all the strips don’t need to be selected. Just make sure you’ve hit the X and deleted the link to the open action’s datablock. If you see any keys in the NLA window, you’re still editing an action. It’s so much easier if you have both the Action and NLA windows open so you can see whether an Action is open or not.

#8

Yes, don’t worry about removing the links to Fake Users for Actions (it’s very easy to do but only if you know how).

Let’s say you want to Boing three times over 30 frames and Topple over 10. Shft-A on Armature and select AC:Boing. Hit N and make the Strip Start at 0.00 and end at 29.00 and set Repeat at 3, so it repeats itself 3 times over 30 frames.

Then you Shft-A to add AC:Topple and make it start at Frame 30 and end at frame 40.

Select each Strip in turn and delete their Actions in the Action Editor and you can then Alt-A.

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#9

Sounds exacty the problem I had. It confused the hell out of me as well.
And the advice above about converting actions to strips seems to be for the previous version of Blender, before 2.40. It doesn’t work anyway.

What you want to do is click the “button” to the left of the name of the armature in the NLA window. The picture looks like the top half of a man (same icon as for the action editor window). When you click this it turns into an NLA icon (little coloured bars). And then your animation will play as you want, with all the actions.

Seems a bit odd though, as

  1. That “button” doesn’t actually look like a button - there’s no visual clues that make it look like it’s possible to click it.
  2. Why is the default mode to only play just the one action? It would have saved me a lot of hassle if it was already in NLA mode to start with.
#10

Thanks for all your help on this, guys.

I wonder why the armature zaps back to its rest position after the last frame? Wouldn’t it make more sense to leave it at the last keyed position? Is this adjustable at the Action level similar to setting the IPO extrapolation mode to be constant?

#11

I wonder why the armature zaps back to its rest position after the last frame? Wouldn’t it make more sense to leave it at the last keyed position?

In the Transform window (NKey) click Hold. This will continue displaying the last frame beyond the end of the selected strip. You can do this for any number of strips in your NLA.