Week '003': The Art of Dismemberment

Hello and welcome to week 3 of Themedior! Today, I invite you to a first-hand observation of the dissection of our main character: Cynefin. I will begin with an explanation of the importance of dividing up body parts, and the basics of the skeleton, bones, and skin. In other words, I invite you to a beginner’s guide to skeletal animation and the beginning of my operation of animating Cynefin.

File 02: Skeletal Animation 

For most of the game animations, I will be harnessing the powers of math, complex algorithms and a huge amount of geometry in an animation technique known as: skeletal animation. Unlike traditional frame-by-frame animation, which requires you to draw each frame individually by hand, skeletal animation uses a skin(a visual layer) and a skeleton composed of bones, which animates/deforms the skin. And the process of creating all of this is known as rigging. So hold on tight as I take you through my process of dismembering and rigging our main character, Cynefin.

Parts and Their Significance

The first step after creating and drawing our main character is to dismember him. Quite literally separating his arms and legs to even the two eyelids on each eye onto different layers. After all of that effort, he should look like this. The same as before. 

Before

After

However, do not fret! It may look the same to us, but for Unity and Live2D, it looks something more like this. 

Live2D

Unity

These are the texture atlas and sprite map which are used by the software for the skin/mesh.

“But why?”, you might ask. By separating each part, I am able to individually assign them to specific deformers and bones and give them their own meshes. This way I can choose which parts affect each other and which parts don’t.

“But what are deformers/bones and meshes?”, you might ask. Another great question, which I shall address in the next section. 

Skeletons, bones, and skin

Now that we have divided our beloved main character into parts, we shall start rigging him, with the first step being skinning. And now to go through the steps of rigging… 

To start us off, we have the skin/mesh. Before we can do anything else with our character, we must first skin him. Skinning is the process of generating a mesh for each individual part of the character. The mesh is composed of vertices that stretch and shrink the parts. Think of a mesh like a net. If you stretch one of the holes in a net, you affect all of the other holes around it. 

An example:

Now that we have our meshes, we can move on to add bones and deformers.

Deformers/bones are what allow us to add movement/distortion to the character. Additionally, it allows us to deform parts/objects together. For example, if you create a deformer for head rotation, you would want to apply it to only the head parts (eyes, hair, etc.) and not the legs. This is where dividing your sprite and creating a proper mesh comes into play.

Live2D

Unity

And voila, we end up with this monstrosity! Although these may look really complex, they can currently only perform basic movements, as of right now.

“But what if we move the upper arm, does the lower arm move in relation to it?” Yet another great question. That comes down to the skeleton, a.k.a. The hierarchical system of bones. Bones/deformers are often never independent of each other. You can link them and add them as children of each other so that the parent bone/deformer also affects the child.

File 02.5: beyond rigging

Now that we created the rig, our main character can now move! But that was only the beginning. To establish his basic movements, we need to set up parameters and weights to allow the bones and skeleton to deform/move the character the way we want it to. Additionally, when thinking of movement, we need physics. I’m not gonna go into it since this post is getting really long, but I will show you some of the results. 

“Good Morning, See You Tomorrow” 

That’s all for this week and I hope you learned a little bit about skeletal animation! Since I didn’t have time to finish adding character skills this week, I’ll include that in next week’s post. In addition, I will be creating the basic character interactions and enemies. See you then!

sources:

if you want to learn more about skeletal animation:

https://en.wikipedia.org/wiki/Skeletal_animation