http://www.clubinfo.bdeb.qc.ca/~theeth/CtrlObject.zip
That files contains some example regarding the Action constraint that was introduced in 2.25. That constraint enable the use of control object to playback Action blocks on selected Armature parts. Anyway, that might sound criptic, but the file is pretty self explanatory.
enjoy!
Martin
you read my mind man…actually i was thinking of asking about it here.got it anyway.
yeah, that’s one of the super powers you get as an admin (well, that and the spandex suit, but I can’t wear THAT in public 
)
If you have any trouble understanding how it works, just ask. After showing it on IRC, it would seem that it’s a little less self explanatory than I thought.
Martin
That’s very cool, theeth. I had no such powerful things were possible!
Very nice,
and clear. One has always something new to learn 
Stefano
BUG
Nice demo, but buggy, IMHO (well, read on, it’s not the demo, it’s the Action Constrain implementation ).
The muscle bulge example does not work correctly :o .
If you keep the arm straigh but move the IKA bone upwards, as if you were rising up the arm, the muscle bulges.
This is certainly due to the fact that the Action constrain is using the absolute rotation of the forearm (Arm2) bone whereas, for a correct implementation, it should use th rotation relative to the arm (Arm1) bone.
I think this might be considered a bug of the Action constrain implementation.
For the door the problem is less severe, because the controlling empty can stay completely separate; nevertheless if, on layer 1, you select ALL and you rotate all, the door opens, which might not be what you want. Same for iris.
In a muscle bulging stuff, the relativity of rotations is absolutely necessary otherwise you might get bulging muscles even if you only rotate the character :o , so I officially ask the coders to take this issue in consideration.
Seeya
Stefano
S68: arghh, I didn’t realise that… I’ll make a bug report on blender.org as soon as I can. Same goes for the linked copies not deforming correctly bug (open the iris and render).
thanky
Martin
Okie
Great demo, in any case, wonder why so few comments…
Stefano
Hm!
I’d been working on how to do a bulge for awhile, and having no luck. Thanks, theeth!!
The bugs are somewhat disconcerting, but the flexibility is impressive!
Nice work, and thanks for helping explain a mystifying part of Blender!
-Bischofftep
P.S. One reason why it might not have gotten much attention is that I’m not sure “elYsiun Chat” is the best place for it. It’s almost a mini-tutorial!
Well, it looks like Alias|Wavefront has added a feature like this to Maya 5, and is marketing it as a major selling point to upgrade. Although the Maya version will probably be more powerful, it’s good to see Blender had it first!
WOW
example 3 is just what we need
i found if you add a little bone the flession in the arm
is more natural, but i’ve no experience with armature
here is what i mean
http://kino3d.com/images/ika.jpg
i’m wrong ?
ciao
Nice theeth, very clear.
Sorry I’m not yet familiar with NLA/actions so when looking at the bulge armature (specificaly the Constraint Action of the Muscle bone) I couldn’d work out how to access the ArmBulge action - I couldn’t see it referenced anywhere else (like in the action window).
Ah stupid me! you select the different actions in the Action window. well now at least you know something to add to the text if you want to “dumb it down”
I am trying to make an action constraint based on your file.
I added my armature
went into posemode
added keys for 2 frames (1 an 10)
clicked bake.
I set the bone to the baked action
90 degree max
0 min
start 1
end 10
OB Empty
When I go to rotate my controler empty, I rotate about 100 deg and it jumps to frame 10 of my action then as I continue to rotate, it jumps to frame 1 again. I’m somewhat new to actions, so I am probably doing something wrong. plz help!
I don’t think I can help you just like this, but if you e-mail me your .blend file, I’ll do my best to solve it.
Martin
Sorry, I ended up figuring it out. I was rotating clockwise assuming that was positive rotation when it was actually negative. When I rotated in the other direction, it seems to work ok. I do have another question though. Say I have a large armature, 20 bones+, that are constrained to an action, is there a way to constrain one bone to the action then copy that contraint to the rest without going to each bone and adding a constraint?
I’m just lazy, thats all
sadly, I don’t think there’s a way to do that right now.
Martin
Thats ok, I was trying your rigging technique on a hand model and after 5 or 6 bones thought there might be somehting that could save me a little time. I haven’t gotten much into python, do you think there would be a way to write a script that would copy one bone’s constrains to the rest of the bones in the armature?
no armature access in Python yet.
Martin