Tutorial: Character Modeling for 3D Applications

Introduction

Character modeling is the process of creating a character within the 3D space of computer programs. The techniques for character modeling are essential for third – and first – person experiences within film, animation, games, and VR training programs. In this article, I explain how to design with intent, how to make a design model – ready, and the process of creating your model. In later lessons, we will continue to finish the model using retopologizing techniques.

Design and Drawing

The first step to designing a character is to understand its purpose in the application or scene. For example, if this character is to be created for a first-person training program, you may only need to model floating hands. This could be how your character is designed for a training application.

Additionally, for film, games, and VR the character's design is key. The design must fit into the world and also visually describe their personality. If they have big, wide eyes, they're probably cartoony and cute. If they wear one sock higher than the other, they might be quirky or stressed. Let their design tell a story about what kind of person they are.

Below I've provided a sample design of the character I will be modeling throughout the article. With it, I've provided a breakdown that explains how his design affects your perception of his character.

Simple Design Breakdown

• Round shapes indicate that the character is nice and friendly; you want the audience to like this character.
• Big eyes show youth and make the character cute; also very expressive.
• Details like the propeller hat and the striped shirt indicate that he's fun and silly.

Model-Ready: Static vs Animated

Once you have a design, it's important to distinguish whether your character is static or animated. This will determine how your go about creating your blueprints for your character model. These blueprints are called orthographic drawings. Orthographic drawings are front, side, and top drawings of your model. You may see these types of drawings for 2D animation or concept art. However, orthographic drawings for 3D character models are different. Below I will explain the different requirements for static and animated orthographic drawings.

Animated

An animated model must be set up properly for rigging. The following requirements are necessary for a character to be bound to a rig:

• The drawings must be done in a T pose or A pose
• They must have a slight bend at the knees and arms
• Fingers and legs must be spread apart
• They must have a blank expression

Skipping any of these steps will make it difficult to achieve clean results with rigging and animation. I've provided some example orthographic, T-pose drawings of the character I will be modeling.

Static

A static model, like a statue or action figure for instance, will hold the same pose. Therefore, it doesn't need a rig. Rather, it just needs to be modeled in the pose and expression the design calls for. The only requirement for your orthographic views is the drawings must be representative of the pose and expression of the finished character model, for all orthographic angles.

Notice, for both of the animated and static drawings the side and front views of the body line up correspondingly. This is important to ensure that the model will be proportionally correct when these blueprints guide you through the modeling process. To continue forward, save each orthographic view as its own .jpg or .png file.

Orthographic View

Now, you're ready to continue onto the modeling section! Since head modeling tends to be more difficult, I've chosen to focus on head modeling for the majority of the section. However, I believe once you are able to understand how to model the head, creating the rest of the character will come easily. Additionally, the same techniques will apply, and I will continue to guide you with step-by-step processes and images.

Modeling

Setup

Now that your orthographic drawings are done you can bring them into your 3D program of choice. To do so, you'll bring them in as image planes. As you can see by the images below, the drawings on the image planes line up accordingly with one another. This is essential. A little bit of difference is okay, but if they're far off, the image planes can warp the proportions of your character model. Once you have your planes in place, we are officially ready to begin modeling.

Tips Before You Start

The three keys to character modeling are symmetry, simplicity, and toggling.

• Symmetry: Throughout each piece of the body, it's important for us to have symmetry to maintain proper functionality for animation.
• Simplicity: Never start with a dense mesh. Starting with a low polygon count will allow you to easily shape the mesh. For instance, in the video I start with a cube, three subdivisions across the depth, width, and height.
• Toggling: It's important to toggle mesh-smoothing on and off. Often, messy geometry will appear clean while the mesh is smoothed.

I do all three of these processes throughout the head modeling video. Watching it will help you understand how these techniques fit into the workflow. Now let's get started!

Modeling The Head

For modeling the head, we are going to go through four stages. These stages will apply to creating the head and the rest of the body.

1. Low Poly-Stage: shaping a low-poly primitive object (a cube for instance) to the piece of the body you are creating.
2. Pre-planning Stage: increase the polygon count and continue to shape the mesh.
3. Planning Stage: plan a space for the details, like the facial features on a head model, for instance.
4. Refinement stage: tweak and add topology as you see fit so you are able to match your design.

Stages one and two

To begin, I'm going to shape a low-poly cube into my character's head. As you watch the video, you'll notice that I use the Translate tool to shape the head, as well as the Insert Edgeloop tool and the Smooth button for further detailing the head. I like using insert edge loop when I need more topology in a particular area. On the other hand, the Smooth button helps when I like to increase the topology on the entire mesh while maintaining the smooth-mesh shape.

Stage three and four

Now that there's more topology, we can begin planning for the eyes, nose, and mouth. You'll be using your orthographic drawings to guide you on the placement for each of these. Again, it's important to follow along with the video so that you can see the process. From here, the steps that follow are:

1. Plan/shape the vertices of your mesh for the facial features.
2. Extrude to build a space for the eye sockets, mouth and nose.
3. Continue to form shape without adding more topology.
4. Slowly add or extrude polygons.
5. Use sculpt tools or soft-selection to match the mesh and orthographic drawings as best as possible.
6. Repeat steps three and four a few times until your topology matches your drawings.

During this stage, I like using the Edgeslide tool, so that when I translate the vertices the head shape will not be altered. Next, you can move onto the refinement stage. After you've finished refining the facial features, you can begin to model the eyes.

Modeling the Eyes

The next step is to make eyeballs that fit inside the head, and for the sockets to fit around them. The process is as follows:

1. Make a sphere.
2. Move and uniformly scale the sphere to fit roughly inside the socket.
3. Rotate the sphere 90 degrees so that the pole is facing outward.
4. Adjust the socket as necessary so that it rests on the eyeball.
5. Shape the iris, pupil, and cornea as demonstrated below.
6. Select the new group and scale the group -1 across the x axis.

Follow the steps as guided with the images below.

Figure 1. Uniformly scale, and translate a sphere to roughly fit inside the socket.
Then rotate the sphere 90 degrees so that the sphere's pole is facing outward.
Figure 2. Adjust the socket to fit around the eye.

Duplicate the eye. The "eye" mesh we do not edit will be the cornea.

Figure 3. Pick a sphere, select the edges as shown, and scale.
Figure 4. Translate the edges back to fit inside the cornea. Now we've created the iris.
5. Select the inner faces, and extrude inward to create the pupil.

Group the eye pieces. Rename the group and then proceed to duplicate it.

Figure 6. Select the new group and scale the group -1 across the x axis.

Now, the only things missing from the head are the eyelids, ears, and neck. However, we won't be doing those until we finish retopologizing our model. As for the hair and eyebrows, I typically like to create low-poly simple shapes.

Patching a Mistake

If it's your first time making a model, it's possible you ran into several complications throughout this process. Below I've provided some possible problems with their corresponding solutions.

• My symmetry tool isn't working properly.
  • This is an indication of asymmetry. Go through the following steps to troubleshoot the problem.
  1. Check for and delete extra vertices and faces.
  2. Make a duplicate and hide or move the original. Next, you'll need to delete half of the duplicate's faces, ensure the vertices that cut down the middle of the mesh are in line with the axis of symmetry, and then use the mirror tool across the axis of symmetry.
  3. Delete the object's history.
• My mesh is asymmetrical.
  • This sometimes happens when you move vertices after forgetting to turn symmetry back on.
  1. Make a duplicate and hide or move the original. Next, you'll need to delete half of the duplicate's faces, ensure the vertices that cut down the middle of the mesh are in line with the axis of symmetry, and then use mirror tool across the axis of symmetry.
• I can't get my character's eyes to fit inside both socket and head.
  • This is likely the case for eyes that have an oval shape or are really far spread apart. For these instances you'll probably need to use a lattice deformer on your geometry. Animating a texture map is also a possible solution.
• When I group and mirror the mesh, it doesn't mirror.

Arms and Edgeloop Placement

Next, I'm going to make another complex piece of geometry: the arm. Before I begin to explain my process, it's important to understand the importance of edgeloop placement. Edgeloops not only allow for you to add topology, but also allow the mesh to bend when it's rigged. At least three edgeloops are needed at joints such as the knuckles, elbows, shoulders, and knees.

Also, remember how we drew a slight bend in the character's arm? You'll need to model that bend. When the character is rigged, the joints will be placed along that bend; this helps the IK joints figure out which way to bend. However, if the joints are placed in a straight line, the joints could bend backwards, giving your character a broken arm or leg.

Modeling The Arms

My process for modeling the arms starts with the fingers and works backwards. I find that doing it this way makes the end mesh cleaner. Following this order, I've simplified process into four stages:

1. Finger Stage: model all fingers and thumb.
2. Palm Stage: model the palm.
3. Attaching Stage: attach the fingers and thumb to the hand.
4. Arm Stage: extrude and shape the arm.

Now that you have a basic understanding of our goal, here are the detailed steps with images to show the process.

Stage one

Figure 1. Make a low-poly cube to model a finger, toggle views to match your drawings.

Figure 2. Add edgeloops at the knuckles, and refine.

Figure 3. Duplicate, tweak, and translate the finger model to create the other fingers.

Figure 4. Model the thumb from a low-poly cube. Refine the thumb. Toggle views to check their placement; then combine the fingers and thumb into one mesh.

Stage two

Figure 6. Create a cube with the proper amount of subdivisions to attach the fingers.
Figure 7. Delete every other edgeloop (for simplicity) and shape the palm.

Note: Doing it this way makes it easy to push the shape of the palm at a lower subdivision, and it ensures that there will be enough geometry to attach the fingers when we increase the topology.

Stage three

Figure 8. Add back in the palm's topology.
Figure 9. Combine the palm and finger mesh.
Figure 10. Attach the fingers.

Note: I prefer using the Target Weld tool to attach the palm to the fingers.

Figure 11. Clean the geometry.

Stage four

Figure 12. Extrude the arm.

Figure 13. Add edgeloops, and ensure that the mesh is hollow.

Once the arm is made, we can duplicate it onto the otherside like we did for the eyeballs. Here's a refresher of the steps:

1. Duplicate and group the arm.
2. Scale the group -1 across the x axis and ungroup the arm.

Modeling The Body

At this point, you've learned most of the techniques needed to finish your character model! The rest of the body follows similar steps we have taken to model the head and arms. If you follow along the video, and follow these steps you'll be in good shape.

1. Ask yourself, "What primitive mesh will work best for each one?"
   • For example: a cylinder works great for pant legs, but a cube could work better for a shoe.
2. Create a vague plan.
   • For example: "I'm going to use the cylinder to create one pant leg, finish the left side of the pants, then use the mirror tool to finish the model."
3. Move, scale and edit the low-poly, primitive mesh to match with the orthographic drawings.
4. Slowly add or extrude polygons.
5. Use sculpt tools or soft-selection to match the mesh and orthographic drawings as best as possible.
6. Repeat steps five and six a few times until your topology matches your drawings.
7. Mirror your model if needed!

Below, are some example images I've provided for each of the remaining parts of the body.

Shirt

Shorts

Leg(s)

Shoe(s)

Great! Your model has been made! However, before we move on, you need to double check these things to make sure you are ready to move onto retopologizing.

• Is your model symmetrical?
• Do your knees and arms have a bend? (only applies if character will be rigged)
• Have you modeled everything for this character?
• Does your character relatively match your drawings?

If none of these questions bring up concerns, then you are ready to move onto the following article for character retopology.

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Source: https://software.intel.com/en-us/articles/character-modeling