Dynamic Bones don't work!

[Hugging_Bear]

Hi Guys,
Two dynamic bones don't work, while the rest do work fine. Why?
Please, watch this video: https://youtu.be/D_Ylskscqv4
Thanks a lot!

[Greenlaw]

Try different settings for the wattle bones. Here's a suggestion...

Torque: 7
Spring: 0.6
Damping: 4

The higher Torque and lower Spring gives it a bigger swing and not-so-much back and forth wiggle, and the high damping makes it slow down and appear to have more weight. Like so...



BTW, you can select all the wattle bones and enter the settings at once to save some time.

[Hugging_Bear]

Try different settings for the wattle bones. Here's a suggestion...

Torque: 7
Spring: 0.6
Damping: 4

The higher Torque and lower Spring gives it a bigger swing but not so much back and forth wiggle, and the high damping makes it slow down and appear to have more weight. Like so...



BTW, you can select all the wattle bones and enter the settings at once to save some time.

Hi Greenlaw,

Thanks for your reply. I tried your suggestion. I get a nice 'back flow' as the character moves forward. But as it lifts its head I still get the 'stiff board' effect (they should stay in a vertical position). Is there a way to combine dynamic and manual animation? As far as I know the 'dynamic' is broken as soon as one starts adding keyframes (if this is even possible).

PS: I made the lower beak bone the parent bone of the wattles bones. This brings the necessary movement during the lifting of the head phase. The remaining problem is there is too much 'springiness' in the movement. But that is a matter of experimentation.

Thanks a lot!

PPS: With a single bone the wattles moves like testicles. So, I added an additional bone to each and reduced the values to the same as the other dynamic bones (0.5, 0.5, 2). Now I got the desired effect.

[Víctor Paredes]

You can try different numbers in real time. Just hit play, open the bone constraints window and drag the numbers right or left.

For parts like this, adding an extra bone with 'independent angle' on, parent of the dynamic ones, helps to give them weight. That 'independent angle' bone works as fake gravity, keeping things pointing down during the entire animation.
I think it could work well here.

Great character, by the way

[Hugging_Bear]

You can try different numbers in real time. Just hit play, open the bone constraints window and drag the numbers right or left.

For parts like this, adding an extra bone with 'independent angle' on, parent of the dynamic ones, helps to give them weight. That 'independent angle' bone works as fake gravity, keeping things pointing down during the entire animation.
I think it could work well here.

Great character, by the way

Hi Victor,

Thanks for your tips. I'm not sure I need more weight in this specific situation since wattles are just a layer of skin. I'm just tried to get rid of the 'testicle-effect' (too much weight). But I'll certainly try your trick, in case I need more weight. BTW - technically it's not 'my' character. I 'stole' it from the Luttrell Psalter. Crazy stuff those medieval monks came up with.
PS: I love your webinars on YouTube. I learned so much! Thank you!

[Greenlaw]

Maybe Bone Dynamics isn't what you really want then?

A lot of times, I don't like to use Bone Dynamics in a character because Bone Dynamics are pretty much going to do what they're going to do, and not necessarily what I want them to do. My feelings about this feature is that it's good for simple motions on objects that will be animated within a limited range, but for characters that have to perform a wide range of slow/fast motions, it can become too fiddly to get them to behave the way I want all the time.

So for dangly items on a character, instead of Bone Dynamics, I'll use a bone chain that I can animate using Sketch Bones. The base of the chain is usually set to Independent angle (as Victor suggests above) so it's always pointing downward regardless of the character's orientation, and it only changes angle when I want it to.

Additional tip: if this dangly bit is positioned within a character's skeleton, it can help to use a duplicated 'remote' control outside of the body. You can see this in the necktie setup for the dinosaur rig seen here...

https://vimeo.com/364548450#t=105

(Actually, you can see the necktie rig more clearly in the second 'rig demo' clip a couple of seconds later.)

As described above, the necktie is rigged with a few bones and its base has independent angle enabled to keep it pointing downward. Then I made a 'doppelganger' of these controls off to the right of the character. This second set of controls is linked to the first using rotation constraints. Once this was setup, I hid the original necktie bones using Shy Bone because I didn't want the animator to touch the original bones, only the remote bones. To animate the necktie, I just 'brush' through the remote necktie bones using Sketch Bones to get the pose I want. It only takes a few seconds to animate this part for an entire scene, and it moves exactly the way I want the first time.

Now I could have let Moho animate the necktie using Bone Dynamics, but I think I would have spent too much time tweaking the settings, and if I had to also address notes from above, it would have been a headache to deal with.

Some things in animation are easier and more satisfying when you animate them by hand.

Hope this helps.

[azureartinc]

Im also having the same issue
My hair dynamics stop working when i need to animate blinks and mouth movements with my smart bones

[Greenlaw]

@Hugging_Bear,

Great! I'm glad you got that working. BTW, I hope it didn't sound like I was saying Bone Dynamics shouldn't be used in a character rig because I do occasionally use it in a character rig myself and find it very useful when used appropriately. I don't like to rely on Bone Dynamics too much for the previously mentioned reason but also because the realism can sometimes look a bit 'digital' and out of place in what's supposed to be a 'traditional' 2D animated cartoon.

But that's mostly subjective of course. I think when that 'digital' look is embraced and used consistently in a production, it can look pretty cool too.

@azureartinc,

Are you saying Bone Dynamics completely stops working when a Smart Bone is activated? I would check that those dangly bones aren't keyframed inside that action because I'm wondering if the Smart Bone Action's animation is overriding the dynamics. (I haven't tested to see if that's what actually happens, so for now it's just a guess.)

Oh, here's something more obvious: Bone Dynamics can be keyframed on and off, so make sure you haven't keyframed it to switch off. If you don't see that on the timeline, maybe it's doing that in one of your actions.

[azureartinc]

https://drive.google.com/file/d/18UrwPt ... share_link the rig is attached here

yes they stop working completely. when i use smart bones.

so I end up not using them thought it could be a bug, cause even in the timeline when you put wind they do not move then pause and render you see they worked its very weird. this is when I don't use smart bones .

[Daxel]

I did a few quick tests with one of my rigs that has dynamic bones and this is what I saw:

You can actually keyframe the rotation of dynamic bones in smart actions, and that animation will be automatically activated by the smartbone like if those were normal bones, so yeah as Greenlaw guessed that is one way to cause your problem. Select only your dynamic bones and check if you see red keyframes on your smart actions.
The thing is that this test is getting quite interesting because I found that if I have the dynamic bones keyframed in a smart action but I don't activate that animation (I don't rotate the smartbone), the bones keep working as dynamic.

The other test I did was to keyframe the rotation of the dynamic bones on the main timeline, and the result was quite surprising for me. The dynamic bones were meeting the rotations keyframed in the timeline but at the same time they were still moving dynamically. I even made the keyframes linear to be sure that it wasn't just the keyframes doing all the movement I was seeing and nope, there was definitelly dynamic movement added to it. Did dynamic bones always work this way? I didn't test it for long, but could this be a cool way to have the control we sometimes need while still having the dynamic bones helping us in the way? Or will this be a problematic workflow for some reason?

[Greenlaw]

https://drive.google.com/file/d/18UrwPt ... share_link the rig is attached here

I looked at your file and, yeah, you have those hair bones keyframed inside more than one your Smart Bone Actions. For example, check the Smart Bone Action called Mouth Open. In this action, the hair bones are keyframes on frame 1 so when you use this Smart Bone Action you're telling Moho to override the bone dynamics with this static pose. Remove this keyframe from the hair bones and you should be able to use this Smart Bone Action while using Bone Dynamics.

Repeat this for other Smart Bones Actions that have the unwanted keyframes.

In the future, I'd be more careful about which items are selected as you create your Smart Bone Action. In a Smart Bone Action, you want to keyframe ONLY what you want the Smart Bone to control. Tip: If you have Auto-Freeze Keys enabled or you're using Freeze Pose out of habit, be sure you're not doing that while editing an Action...that's asking for trouble.

Hope this helps.

@Daxel, thanks for confirming my suspicions and, yeah, that was an interesting troubleshooting exercise.

[chucky]

Often playback of dynamic bones does not work in the playback unless you start after frame 0.
Try playing from frame 1 or rendering.
This might be specific to certain hardware profiles, I don't know.

[azureartinc]

thank you will trouble fix now

[Greenlaw]

I finally got around to testing this and, yeah, keyframing the bones inside a Smart Bone Action (SBA) does disable the physics on the bones when the Smart Bone is active on the Mainline.

Curiously, the physics do work while editing the SBA. Also, if I don't use the Smart Bone and I keyframe the bones on the Mainline, the physics remain active on top of the keyframed animation.

Based on this observation, I would think physics should work when using a Smart Bone so maybe it's a bug? If not a bug, it's a limitation anyway.

I have a few tricks for overriding certain Smart Bone limitations but not sure any of them will work in this situation yet. Will look into that when I have time.