Track to / Damped Track lagging behind when animated - Need help

Support Animation and Rigging
1

Hello!

I am facing some issues with tracking constraints and I was wondering if anybody knows what I can try to fix my problem.

I created a becker rudder in Blender, rigged it and animated it. A becker rudder is a rudder which is typically used in tug boats. The main rudder is extended by an additional “flap” which is connected to the rudder via joints and its rotation is controlled over a stick inside a tube which sits on top. I hope this makes sense. But if you watch the video, it should be clear how it works.

Rigging the rudder went easier than expected. In version 1 I used a few empties and used an object constraint directly on the cylinder which goes in the tube. The track to constraint points toward the empty which sits at the end of the “flap” which is parented to it.
Version 1 looks terrible when animated. It is lagging a lot. I did some googling and most people used bones for similar use cases so I created version 2 with bones.

grafik
grafik2962×963 395 KB

Also I used Damped Track instead of Track To. I don’t know what to think of version 2. In theory it looks better but I think it also lags behind every now and then. When I rotate the main control empty which is fixed to the main axle, I get no lagging issues. But when I play the animation it looks terrible. Funnily - when it lags and I select the cylinder and just hit “R” (Rotate) it snaps into play correctly. But should I go to every frame, hit R and then Render? NO! That can’t be the solution. 280 frames is a lot for me…

Any ideas what I can do differently?

Beckerruder.blend (1.9 MB)

I uploaded the Blend file in case you want to try.

Also here is the version 1 animated: https://www.youtube.com/watch?v=HtbbwCa5Bew
And version 2 (with bones & damped tracking - blend file attached): https://youtu.be/-0KRH3RCCM0

I am very grateful for any tips or help.

Thanks!

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Here is another video where I reproduce the issue and explain what exactly I mean.

3

It sounds/looks like a dependancy cycle, but I couldn’t find where the loop came in. When I parented the part to the armature with autoweights instead of parenting it to the bone (There’s only one bone in the armature, so it’s a very similar end result) I stopped having the issue.

Is that something that might work for you? Or does it need to be parented directly to the bone instead of with armature deform?

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It’s buttery smooth now. Thank you!

I don’t see a reason why parenting with automated weights should be an issue in my case. As you say, it’s only this one bone.

I read about dependancy cycle but I didn’t think it could be the problem in my use case.

Do you have any idea as to why it works when parenting w/ automated weights? Just curious.

THANKS! You’re my hero of the day! :smiley:

I’m currently rendering the animation again. Will report back in case I still experience issues but so far everything looks good

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5

Not a one. Sorry.

6

No worries.

The animation finished rendering and it looks good now. No more lagging :slight_smile:

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7

I see this is solved, but it caught my interest a bit because it worked one way (weighting and armature deform), but not another way (when parented to the bone) and it should have.

Anyway, there is a cyclic dependency error in the file posted

error1
error11680×1050 240 KB

The message is too cryptic for me to figure out, especially since you’ve got the results you want…

Randy

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