Question about character design for bones

Wondering how to accomplish a certain animation task? Ask here.

Moderators: Víctor Paredes, Belgarath, slowtiger

Post Reply
Popa
Posts: 27
Joined: Thu May 11, 2023 11:21 am

Question about character design for bones

Post by Popa »

I'm actualy done with my very first character design and there is just one thing troubling me and thats the arms, well legs as well since its the same concept.
I've watched some guides where they draw both forearm and upper arm in separate layer, but also designs where its just one solid arm.
Which one is better for rigging/bones in your opinion?
I'm a totaly new to moho and animating just to clarify this beforehand. Right now Im gonna jump into Moho and test it out for myself but I also want a 2nd opinion from more expierenced animators here.

This is the arm I'm talking about.

Image

I'm aware that if 2 parts are better I need to make a better concealment on the elbow, but the question is can I go for one solid arm and have just as much flexibility?

Thanks in advance!
User avatar
SimplSam
Posts: 1048
Joined: Thu Mar 13, 2014 5:09 pm
Location: London, UK
Contact:

Re: Question about character design for bones

Post by SimplSam »

The big advantage of a '2-piece' arm is if you need to have the one part behind the torso and the other in-front at the same time. i.e. During 3/4 pose or a turn, the upper might be behind, but the lower needs to be positioned in front.

If required, you may be able to achieve this quickly by simply creating a reference layer, and positing the original behind, and the reference in front - with parts of the 'front' layer hidden by hide stroke or reducing color opacity. In that case - no need to actually split the arm.

Generally this is not required for legs, unless you are doing something wacky with your character.
Moho 14.1 » Win 11 Pro 64GB » NVIDIA GTX 1080ti 11GB
Moho 14.1 » Mac mini 2012 8GB » macOS 10.15 Catalina
Tube: SimplSam


Sam
Popa
Posts: 27
Joined: Thu May 11, 2023 11:21 am

Re: Question about character design for bones

Post by Popa »

SimplSam wrote: Wed Oct 04, 2023 12:16 am The big advantage of a '2-piece' arm is if you need to have the one part behind the torso and the other in-front at the same time. i.e. During 3/4 pose or a turn, the upper might be behind, but the lower needs to be positioned in front.

If required, you may be able to achieve this quickly by simply creating a reference layer, and positing the original behind, and the reference in front - with parts of the 'front' layer hidden by hide stroke or reducing color opacity. In that case - no need to actually split the arm.

Generally this is not required for legs, unless you are doing something wacky with your character.
Thanks for your input! I will draw 2 parts and avoid all future problems. I'm gonna be animating fighting scenes so I'm not sure how wacky it can get so I will do those as well.
User avatar
Greenlaw
Posts: 9269
Joined: Mon Jun 19, 2006 5:45 pm
Location: Los Angeles
Contact:

Re: Question about character design for bones

Post by Greenlaw »

I agree with SimplSam: splitting the art into two pieces gives you the most flexibility for posing. Fortunately, Moho makes it easy to do this.

The sleeve design intrigued me, so I hope you don't mind that I used it to create a 'cheap' version of a two-piece setup...well, okay, three pieces...

Image

Here's the setup: First, I drew the whole arm as one layer, and I split the elbow area into two shapes with a hidden shared edge...

Image

...then I duplicated this layer, named it ArmLoL, and knocked out the shapes I didn't need in this layer. Like so...

Image

Then I made another duplicate of the original and named it ArmUpL, and knocked out the bits I didn't want in that layer...

Image

I kept the original full arm layer and moved it outside the rig, and hid it. This version is kept as a backup. The third part is the shoulder, which I kept outside of the arm group so I could move it in front or behind the arm group.

Normally, I would make a Smart Bone Dial to control the sorting of the layers, and instead of having it shuffle the layer order, I prefer to make duplicate or reference layers of the limbs around the body and animate their visibility. This is because I want the flexibility to change the rig when needed, but animating Layer Order with a Smart Bone locks me into only what the Smart Bone allows. Animating visibility with the Smart Bone Dial means I can insert new layers and move layers around manually without breaking the Smart Bone Action.

In this demo rig above, however, I'm just manually moving the layers up and down the stack where I need them. For simpler rigs, this is my default method...it's easy enough to set up, easy to animate, and anything more is just overkill to me. Tip: use Timeline Visibility to keep the animated layer order keyframes visible when animating other layers.

The only Smart Bone in use is for the lower arm bone. This is used to change the curvature inside the elbow to a crease and to make the outside more rounded.

Anyway, if anyone cares to look at this demo file, it's here: armRigDemo_B_01.zip

If this rig were for production use, I'd make the 'roll' around the shoulder smoother, improve the elbow bend, and maybe add a proper fold line in the elbow. Oh, and Shy the elbow bone because you don't want to keyframe that. But this is a good example of how you can seamlessly split a limb to wrap around itself and the rest of the body pretty easily in Moho.
Last edited by Greenlaw on Thu Oct 05, 2023 4:46 pm, edited 7 times in total.
User avatar
Greenlaw
Posts: 9269
Joined: Mon Jun 19, 2006 5:45 pm
Location: Los Angeles
Contact:

Re: Question about character design for bones

Post by Greenlaw »

One more thing: If you look at the split shape in the elbow area, you'll notice an extra point in the center of the curve. I used this to pull the line over the shape in the other limb layer. This is necessary to prevent a narrow gap that can occur during render caused by anti-aliasing. This error appears when drawings are split into two separate layers like this.

Another solution to this is to render your animation with no-antialiasing, and the gap will be gone. Then, you'll have to add anti-aliasing as a post-effect in a compositing program. I like using the free OLM Smoother plugin for After Effects, which was created precisely for this task.
Last edited by Greenlaw on Thu Oct 05, 2023 4:48 pm, edited 1 time in total.
User avatar
SimplSam
Posts: 1048
Joined: Thu Mar 13, 2014 5:09 pm
Location: London, UK
Contact:

Re: Question about character design for bones

Post by SimplSam »

I will also refer you to one of Greenlaw's other posts on the subject: viewtopic.php?p=210873#p210873, where demos part of the arm moving front and rear.

Image
Moho 14.1 » Win 11 Pro 64GB » NVIDIA GTX 1080ti 11GB
Moho 14.1 » Mac mini 2012 8GB » macOS 10.15 Catalina
Tube: SimplSam


Sam
Popa
Posts: 27
Joined: Thu May 11, 2023 11:21 am

Re: Question about character design for bones

Post by Popa »

Greenlaw wrote: Wed Oct 04, 2023 10:32 pm
You guys are awsome!!! Im suprised how well you performed the armbending with such a bad elbow concealment. Yesterday I adjusted everything because I wasnt even happy about the placement of my elbow either, made the lower arm look too small. I loved the example Sam showed of your previous work, that elbow bend (ripple) made the animation that much more lively.

Im not sure if Im gonna set up a dial because that movement behind the back wont occur that often in my animation. I think so atleast, if I get frustrated Im gonna look back in this thread for sure. Its good to know there is such an option.

I cant talk in depth or react to your animation suggestions since Im a total newbie. I will be starting my first animation tomorrow, rigging my first character in depth. I know what to do vaguely, I bought the proper guidement that explains everything in steps. I studied it once but the best learning proces will be doing it myself. I will report back in a few days once I've made all the mistakes. lol

This is what my final arm design looks like. My worries are absolutely gone since you made it work with my previous design.

Image

I have 5 layers there: shoulder, 2 arms, elbow and hand.
User avatar
Fabs
Posts: 2
Joined: Thu Jan 11, 2024 3:46 pm

Re: Question about character design for bones

Post by Fabs »

hello I need help, how can I convert bitmap to wrap, that is only available in pemium version?
Post Reply