Bone dynamics go beserk

Galbatron · Post by **Galbatron** » Fri Dec 04, 2009 4:52 pm

When playing an animation in ASP 6.1 that use bone dynamics, they work work like they should, however only after the first cycle. During the first cycle the movement during the dynamics part is much too fast and not 'dynamic'. During the second cycle and so on the dynamics do work. When exporting the sequence as SWF or AVI the behaviour is the same as during the first play cycle (dynamics go bezerk) so i can't make a proper export with dynamics. Am I doing something wrong (every cycle should look the same, should it not?) or is this a bug?
Examples:
www.epdisch.com/tail_waggle_dynamics.anme (plays right AFTER the first cycle)
www.epdisch.com/tail_waggle_dynamics.swf (tail goes bezerk at the end)

BTW: I'm on Windows XP SP2.

Post by **Víctor Paredes** » Fri Dec 04, 2009 6:05 pm

Ok, it's far to be a bug, so maybe an administrator should move this thread to some place else.

Some tips. First, try to not use angle constraints limitations for dynamic bones, generally constraints angle limits cut suddenly the movement and the movement looks less dynamic.
To limit the movement, play with the values, decrease the torque force, for example. remember you can add decimal numbers (0.5, as example).

Second, your animation has the dynamic bones working since frame 94, that's why on that point it becomes crazy. You can turn on/off the dynamic bones on any frame, so if you want to have dymanics an whole the animation, be sure to turn it on on frame 1.

Third, try to not move manually the dynamics bones (only on very neccesary cases). Your final tail bone is being controlled by the other tail bone, so the dynamic goes crazy because the final tail bone is moving it self, being moved by the other bone, and moved by the dynamic. It's just crazy, that is not how dynamics works.

Dynamic works this way: a child bone is automatically animated on relation of the movement of its parent bones.
When you make a bone dynamic, generally you don't touch it anymore.

I recommend you to make a search on tutorial to see how dynamics bones have to be prepared, I'm sure there it will be better explained.

Galbatron · Post by **Galbatron** » Sat Dec 05, 2009 11:03 am

selgin wrote:Some tips. First, ...Second,.... Third...

When you make a bone dynamic, generally you don't touch it anymore.

Thank you for your tips Selgin! They really help me.
My apologies for using the wrong forum. I'm glad it's not a bug, so I can make it better by studying ASP6 more.

There's only one thing that keeps we wondering:
Why does the crazyness only occur during the first play cycle? During the second, third etc. behaviour is like I want it (although I programmed it wrongly).

Rai López · Post by **Rai López** » Sat Dec 05, 2009 1:54 pm

EY, Selgin! I think you are being too much conservative in some aspects here! Aaalthough I understand some things you said are more like advices to start playing with dynamics, BUT there is much more you can do with it as soon as someone get more practice, and it's good to know it!

So this is my thoughts: I have used dynamic bones in all the imaginable ways and setups (or I think so...) and I never have had any problems with it, well, as far as I have taking in to account several points:

1-. Bone size! Cause the dynamic movement it seems to be calculated proportionately, I mean, based in his original size (not the actual possible scaled size), so don't expect that a bone with 2 units of length in frame 0, behave the same that a bone of 0.25 of length, just because you use the same "Torque/Spring/Damping" combination of forces for both.

2-. Torque/Spring/Damping forces, as selgin still said, you MUST play with this values until you get the "desired" results, the good thing is you can press play and adjust this parameters (dragging into the numerical boxes with the right mouse button) to see the result of your changes in real time! Although you should do several F5 tests to see the "real" bones behavior in the final animation. Ah! And don't forget to disable "Allow Frame Skipping" into the Animation menu to avoid strange bone preview jumps...

3-. Well, you can use angle constraints but carefully, I mean, as far as you adjust the dynamic parameters accordingly, treating that your bones "collide" with that limits as softly as possible... I agree this is the most tricky part (and it reminds me to one feature request I always have wanted to do), cause you can't predict what kind of movements your character will do and, unfortunately, angle constraints are not animatable (don't think my feature request have something to do with that), so... a limited use here, but, as any other un-animatable feature, it can be useful in some cases...

So there is no problem with animate dynamic bones (for something dynamics animation are calculated after keyframe animation) and there is no problem mixing several dynamic bones with different dynamics and controlling settings into the same bone chain, indeed, you must play with all this to get less artificial and more complex/rich movemets in your automatic animations! You just have to play a little more with it and have fun

Now... your issue! Well I'd advice you to open the angle of constrains a little (or as much as you can at least) and play with dynamic setting of the "staartaanzet", you can decrease Torque and, maybe Spring/Damping force, and go increase'em gradually until you be more or less content with the results, then press "F5" to obseve... I understand you are controlling the "staartpunt" angle based on "staartaanzet" angle to get more "curved" tail animations, and (although maybe you could get similar results in many other ways...) I don't see a problem with it (so maybe we be not crazy at all!

), as long as you know what are you doing and adjust the other parameters accordingly.

I'm not sure what exactly you mean with "cycle" in this case but, as selgin still said (again), your "staartaanzet" dynamics starts in frame 94 (see the keyframe on the Bone Dynamics animation channel in timeline) and, cause of that, you get the jumps thereafter... although it shouldn't happen once you make the necessary dynamic adjustments.

Uff... that's all

Galbatron · Post by **Galbatron** » Sat Dec 05, 2009 2:53 pm

Ramón López wrote:I'm not sure what exactly you mean with "cycle"

Thank you for your extensive addition!
I will start with modest experiments to keep track of everything and why it works that way.
What I mean with cycle: just playing the animation in ASP6 from start to end point (frame 1 - 120). When the playback is not stopped in ASP the animation starts over (cycle 2) and over (cycle 3) etc. again.
When playing the animation the first time in ASP the behaviour is not like desired (and like in the export) but when playback is completed and starting over the second time the bones behave very differently and more like I like to them to behave. Maybe the first playback has triggered some parameters that make the behaviour different during the second cycle?
When stopping and starting over from frame 1 the behaviour is like cycle 2, 3 etc.
The first jerky playback occurs ONLY directly after loading and playing the file in ASP.

BTW: when hitting F5 there's a preview rendered, but after the progress bar has disappeared there's no playback and I can't find any file on my hard drive that 's rendered either.

Rai López · Post by **Rai López** » Sat Dec 05, 2009 3:36 pm

Oh, yeah, that's weird... so I think you could finally call it a "bug".

Anyway... the other point that was implicit but maybe I should have added is...

4.- Never trust (very much at least) in bone dynamics real time previews!

Of couse it could/should be improved, so maybe you have a good "feature request" here as well, but, that's the reason I emphasized about the good "F5" habit... that bring us to your other issue BTW...

So, first of all, have you QuickTime installed in your computer? Cause this feature have (good) use of it... If you have not it installed, and you are on Windows, maybe you could assing the *.mov extension to another video player like "VideoLAN" that support the format as well, although I've not tested it and I'm not sure if it could works with Anime Studio in that way... Anyway, the feature well worth the effort of install QuickTime itself, besides that you'll have interesting codecs to export at the same time, so let us know what exactly your situation is about this matter.

PS: Oh, can you look at "C:\Documents and Settings\your Windows session name\Local Settings?\Temp" to see if a file called ".anme_preview.mov" have been create there? It's just for curiosity...

Post by **Víctor Paredes** » Sat Dec 05, 2009 7:24 pm

Thanks for the tips, ramón

I know my post was too conservative, but I just try to explain the basics. I love to experiment with bones and points (no more than you, anyway

), but dynamics are not an easy task.

PD: I never thought on play with the values with the animation playing, that's a good tip. It's my fault of creativity, anyway. I always change particle values on real time, but never thought on dynamics bones...

Galbatron · Post by **Galbatron** » Fri Dec 18, 2009 1:12 am

Ramón López wrote: PS: Oh, can you look at "C:\Documents and Settings\your Windows session name\Local Settings?\Temp" to see if a file called ".anme_preview.mov" have been create there? It's just for curiosity...

Yes it's there.
But i can't get it to start automatically, even when quicktime is installed. Using Ctrl + E works faster as the exported vmw/swf starts immediately (Media Player/Irfanview) after export.

Thanks for your tips!