Connecting bones to tracks

Support Animation and Rigging
1

Hello, all. I’ve been working with my younger brother on a Blender project he hopes to display for Halloween; he has made a textured model of his own head in Blender, and is now trying to animate it. He has a lot of Blender experience, whereas I have just about none, but this is his first time working with animation in Blender. The plan is to animate the head model using motion capture videos of his face. We were supposed to be further on in the process by now but life got in the way.

We seem to have hit a wall in connecting the model to the motion capture video. The test video we have has been tracked quite nicely, and my brother has placed the head of a bone at each point where he wore a motion-capture dot. The bones aren’t connected to any sort of larger armature at this point, but he made one of them the driver for a shape key he made for raising an eyebrow, and we started trying to connect that bone to the corresponding track from the video using a bone constraint. The problem is that we’ve tried every kind of constraint available and none of them seem to result in the bone following the movement of the track. Some of them cause the bone to be relocated to the cursor, or to become much larger or rotated in different direction, but all of them result in a bone which does not move or transform at all as the tracks move.

We’ve looked at several tutorials but all of them seem to involve a much more complicated armature then we’ve got, and most of them are for older versions of Blender (we’re using the 2.71 release candidate, and my brother is not keen on updating in the middle of things).

Does anyone have an idea where we’re going wrong?

Edit: I’ve acquired permission to share the .blend file we were working on. We were last trying to use a bone constraint to connect the bone called brow.L.I to Track.003. I can’t seem to upload any attachments, so have a Dropbox link: https://dl.dropboxusercontent.com/u/107628868/ME16.blend

Edited again: Halloween’s gone by, but we’d still much appreciate advice on this issue.

2

Well, have you tried linking empty to track in the under the geometry tab in motion tracking? I can’t look at the blend file right now because I’m on my tablet but when I have time I’ll look at it. Try the above method, there should be a geometry tab on the right in motion tracking, select a marker, expand the tab, and click on link empty to track. Play the animation, the empties should move according to the motion of the marker. Then parent each bone to the corresponding empty. That should work :slight_smile:

3

Hey, I’m taking a look at it (also realizing that yes you’d have to link empty to track, duh) and I have no idea why when I link one track to an empty it links every track. I’ll have a good look at it.

4

Are you sure?
Well, first of all, delete all the empties, and select the track named T_brow.L.l and “Link Empty to Track” again. I’m pretty sure all the empties will come back again (at first it looks like that T_brow.L.l wasn’t there but if it is then don’t delete the empty tracks). Scaling the empties down might be easier for you to visualize. Then, select the bone that you want it to connect to the empty. I would recommend brow.L.l, go to bone constraints, and click on “Copy Location”. For the target, select T_brow.L.l. It should work, at least it worked for me. Then do Copy Location for the rest of the bones. It’s just that you have to scale the head, and the empties should be where they are according to the model head you made. :slight_smile:

5

Alright, well, it looks like that you track the bone to the wrong empty…
The bone “brow.L.l” should be tracked to the empty named “T_brow.L.l” by using “Copy Location” bone constraint.
Is that helpful?