Maintaining facial expression a through head turn

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Ahayut
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Maintaining facial expression a through head turn

Post by Ahayut » Fri Apr 19, 2019 3:12 pm

Hi everyone,

I've just finished a pretty low budget short film as a rigger/animator. All in all went pretty smooth but not without some difficulties that were very hard if not impossibly for me to overcome.

I have now pitched Moho to an animation studio as a software to be used for a local TV show. I'm a bit nervous as I know my knowledge in Moho is not thorough enough but I am confident I can pull it off.

I have two and a half bugging question:

https://www.youtube.com/watch?v=EaA3M4D ... 21&t=1092s

1. How to maintain a facial expression structure around head turns extremities?
In the attched above timeless masterpiece (Victor Peredes interviewing Jeremy Purcell) min 23 Jeremy shows example of expressions working seamlessly over the stretch of a head turn. I see he uses Switch Layer for that but I can't seem to be able to work out how this happends. I found that it's very hard to have one expression turning R/L or up/down so how does this happends so smoothly over the whole spectrum with several expressions. what I found extremely difficult is keeping the "gray area" where head turn both up and right for example maintaining any kind of decent structure.

1.5 how should I go about controlling the eyes?
Something that seemed so easy became a terrible nuisance, I couldn't control them with Position Control Bone because it meant I had to "chase" the character as he moves in the frame, also if it tilts head I couldn't pivot the eye along. I ended up just binding the eyes to the head bone and moving it manually as I needed them- in short, don't try this at home.

2. Last but not least, how to control limbs over body turns?
When I created body body turn it became extremely hard to control limbs. That was because it was hard to predict how the newly positioned point will react to each other when I lifted a leg. I used Layer Binding and Point Binding (should I have used Flexi Binding?). It might be usefull to explain that the charatcer was extremely complex, Disney style, with fabrics, shadow, lines all over etc.

I assume no one will have the time to give all the answers, but I will appreciate any input, or links, or literature or what not.

I"ll be happy to sent examples of the character if asked/needed, and if anyone wants to know who I am you can visit my pretty bare instagram (assaf_hayut) not uploaded with the work mentioned.

Many thanks,
Assaf
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Maestral
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Re: Maintaining facial expression a through head turn

Post by Maestral » Fri Apr 19, 2019 3:54 pm

Hi!

To me, it looks like the proper answer to your questions lays somewhere in between the design and layer structure.
You are right, switch layers are used for different eyes but the rotation itself is solved through the Actions and Smart Bones. Once you have a grip on these two, you`ll quickly figure out how does it affects the design of the character and layer structure.

There`s a ton of tutorials you`ll find with search keywords like: moho + smart bones / smart warp / actions / layer order (to name a few)
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Greenlaw
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Re: Maintaining facial expression a through head turn

Post by Greenlaw » Fri Apr 19, 2019 9:22 pm

Hi Assaf,

Creating a fully turning head that transitions smoothly can get really tricky and, IMO, for most cartoon animation it's usually not worth the effort.

What I typically do for the rigs we use at work (TV animation production) is to set up a smooth turn from front to slightly wider than 3qtr and then snap to a profile (via Switch layer.) If the views align well, the transition can look reasonably smooth. If a full turn is expected for the character, I'll continue from the profile to snap to a smooth back 3qtr view to back view animation. If the turn is animated slowly, you will see the 'pop' but in more practical timing, you'll probably never notice it.

Trust me, separating the front/3Q view and profile view is MUCH easier to work with than trying to rig a smooth continuous animation from front to back views. It will also be easier to animate and adapt the rig for unanticipated situations.

To see examples of this setup in action, check out our 2D segments in Boss Baby: Back In Business on Netflix. All the 2D characters in this show are set up this way.

As for head tilts, I find it easier to bind the face elements to a 'face' bone and simply transform the bone up and down in a 'head pitch' SBD. (You'll also want to animate the ears and hairline in the SBD.) When in profile view, you don't need the 'tilt' applied at all, just tilt the head bone.

Generally speaking, I like to use y-axis bone transforms for head tilts, and avoid direct point animation in the tilt if I can. When you start including point animation here, you risk running into conflicting Actions during the turn Action, which can be a headache to deal with.

If you must animate the points in a tilt, try to restrict the motion to only in the Y-axis. It may be necessary to add more points in the artwork to do this. In side-to-side Actions, keep the point motion to the x-axis. This will insure there is no conflict between the two Actions.

Alternatively, you can use a hidden SBD to compensate for the conflicts. Here's an excellent video from Mult Rush explaining the technique:

https://www.youtube.com/watch?v=M0RJEjA21f8

I sometimes use this technique and it works great.

But most of the time, it's better to just keep things simple. Keeping it simple gives the animators more flexibility to adapt the rig for special (i.e., unexpected) poses and animations from the storyboard artists.

Hope this helps, and good luck with your series!
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Designspaceman
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Re: Maintaining facial expression a through head turn

Post by Designspaceman » Sat Apr 20, 2019 2:19 pm

Hi Moho People,
I agree with Greenlaw to separate the view angles. This is mostly the best way.
But im my actual animation I'm going just the other way: I do a full 360° turn of the whole character. My steps for this are:
1. Design the character. What should the puppet be able of? This determines wheather I do the turms with switches or with smart bones.
2. So I decide to do a full 360° character. Therefore I must have an idea of how I can do the turn without creating a puppet that is too complex to animate fluidly. Im my case I have as few points as possible. In addition I have a plan for what I can do with masking and changing the layer ordering.
3. For the face: I create all expressions first with smart bones: mouth expressions and what is needed for lip sinc, eyes and brows an so on. This is done with point editing. For the mouth I use the technique from Troy Picou (check ot his video here: https://www.youtube.com/watch?v=nTlbqCYx6mY&t=282s). This is very clever, if your character is not too complex.
4. Then I carefully do the headturn in steps: from front to 3/4 view to side view and so on. This is a lot of trying and checking. For the movement of mouth and eyes an so on I use layer translation (I don't want to get them into conflict with the smart actions for the expressions). And of course masking and layer ordering.

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The example is an unfinished prototype that needs tweeking for the mouth. But it shows how it can work. (use right click / view image to see the whole image)
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Ahayut
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Re: Maintaining facial expression a through head turn

Post by Ahayut » Sun Apr 21, 2019 8:41 am

Hey Guys,
Many many thanks for your input.
I'll def check the links (I cant believe there're still tutorials I haven't yet watched) :D
Thanks for sharing your work and examples, I'll try them and report back if and when we will get to the rigging stage.
Cheers,
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Re: Maintaining facial expression a through head turn

Post by amanandink » Wed Apr 24, 2019 10:24 am

hey Ahayut

I would totally agree with what everyone has said before on the different rigs for different body views. it is so much easier to handle and control. and just to add a bit of context to the Puffin Rock models. The Oona rig I showed, I think this was at the end of season 2 and was a maybe the 7th or 8th version of the rig. We work with referenced models and no one can find a bug in a rig like a team of animators, so we are constantly updating and fixing minor issues.
the oona design was also an easier design to be able to deal with the amount of head turn we got into the rig. the major issue was the beak, the eyes and face were the easier part. We approached it by doing one expression first, the neutral eyes 1, we get that working and approved in the head turn and blinking. we then duplicate the eyes and alter its design to create the next expression, so it theory you only need to re-do the adjustments for each expression. but that is still alot of work for the rigger, and its probably well over a month of work gone into just this one rig.
and we also had safe zones, there were certain combinations for smart actions that just broke everything, so the animators were not allowed to have her tilt look up and to turn her head to the right. beaks and eyes would detach

in terms of body elements changing on a body turn, we actually tend to not build that into the rig, the design elements will rotate but the shoulder/leg bones tend to stay stationary, on the last show we did this was a decision made by the animation supervisor, he wanted to have the control of the position the shoulders/legs would end up in and didnt want the smart action putting them in an unpredictable place in a body turn. on all our rigs we have a back and forth time with the animation supervisor and some leads to they have input on the rigging and what they want control of.

I hope this helps
Jeremy
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Greenlaw
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Re: Maintaining facial expression a through head turn

Post by Greenlaw » Wed Apr 24, 2019 12:55 pm

amanandink wrote:...in terms of body elements changing on a body turn, we actually tend to not build that into the rig, the design elements will rotate but the shoulder/leg bones tend to stay stationary, on the last show we did this was a decision made by the animation supervisor...
I absolutely agree with this. In the earliest rigs I created for shows like All Hail King Julien, I built in the positional animations for arms and legs in the 'Body Turn' Smart Bone Dial (SBD) but this became annoying to work with during animation because I was constantly fighting Moho over where I wanted to move the limbs and where the SBD wanted to move them. Also, whenever I added a slight body turn, the SBD would move the limbs when I might actually want them to stay put.

Eventually, I wound up removing the limb positioning animations from the SBD Actions and taking back control for myself. I've avoiding baking in limb position animation in SBD Actions ever since.

Consider carefully how much automation you build into your rigs because the more animation you build into the SBDs, the more restricted the rig becomes to what the automation allows. IMO, some animation is better left for the animator to decide. Imagine that! :)
D.R. Greenlaw
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Ahayut
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Re: Maintaining facial expression a through head turn

Post by Ahayut » Thu Apr 25, 2019 4:41 pm

Thanks so much Jeremy and Greenlaw, great to have such an active community here.

I must say I just figured out that, as recommended here, as far as body turn goes the easiest would be to have as little action on body parts and limbs as possible. In some simple rigs I've just designed we made the torso in a way that will minimises action on limbs, and that was the most flexible rig I've done so far.

I'm practicing now expressions with the input given in this thread. I'll post back.

Thanks again
amanandink
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Re: Maintaining facial expression a through head turn

Post by amanandink » Thu Apr 25, 2019 5:11 pm

oh I should add something that we have found usefully, on the body turn, because the limbs are not moving, we build in guide dots for the shoulder and hip placements, just little vector circles that are set to only appear in moho (do not render) and they follow the smart action of the turn. it gives a guide for the animator as to where the shoulder and hips should be to stay on model
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Re: Maintaining facial expression a through head turn

Post by slowtiger » Fri Apr 26, 2019 10:40 am

In a different context I just was reminded of what I was taught: "Every head turn involves a change of expression". So maybe you just need a neutral look which is maintained in each position.
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Greenlaw
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Re: Maintaining facial expression a through head turn

Post by Greenlaw » Fri Apr 26, 2019 5:12 pm

amanandink wrote:...on the body turn, because the limbs are not moving, we build in guide dots for the shoulder and hip placements, just little vector circles that are set to only appear in moho (do not render) and they follow the smart action of the turn. it gives a guide for the animator as to where the shoulder and hips should be to stay on model
That's a great tip Jeremy! I'll have to try that in my next rig.

I usually relied on hitting Reset to make the selected 'legUp' or 'armUp' bone snap back to its 'default' position but that has obvious limitations. I've also used Regular Actions for common limb positions for the character...but then I might forget those Actions are there to use. (As do the animators I work with.) :)

Ahayut wrote:...I must say I just figured out that, as recommended here, as far as body turn goes the easiest would be to have as little action on body parts and limbs as possible...
You got it!

When I'm setting up turns, I try to limit the motions to only horizontal moves and scaling during in a Turn for each major body part (head, torso, legR, legL, maybe a hat, etc.,...) Each of these parts will have it's on Smart Bone Dial. If you have the set up and laid out well, animating the character can go very quickly. Anything else might go into a special SBD or I'll just leave it for normal keyframing.

When I need to hit a pose or motion that's difficult for the 'universal' rig, I generally avoid building that into the master version of that rig. Instead, I'll add the unique capabilities into a 'one-off' modified or alternative rig. It keeps the 'universal rig' from getting unnecessarily bloated and slow, and makes it more more, well, 'universal'.
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