How to Stylize and Model 'Toon Humans - Chapter 1: Concept and Modeling

Introduction

Welcome to the second part of the stylized character series, this time dedicated to the creation of a human character. As in the previous tutorial (The Boxing Kangaroo), we will develop the character concept during the modeling process.

There are many ways to skin a cat. The same is true about character creation. In the previous tutorial we used the method of sketching an idea in 2D, creating a low polygon topological base in 3ds Max, and then exporting it to ZBrush to establish proportions and detail. In this tutorial we will follow a different path, exploring the power of ZSpheres to reach a 3D concept quickly.

During this chapter you will notice that the character will be changing. With this approach, we can easily modify the character as we explore its proportions and incorporate new ideas along the way. The character starts skinny and becomes buffed up and more angular.

In the first tutorial we followed a very detailed step-by-step approach. This time we will assume that you have acquired those skills and only new techniques will be detailed. Also, during the writing of the article ZBrush 4 has been released, so we will use this software in order to benefit from some of its new features.

ZSpheres 1

Let's start by building the structure of our character. ZSpheres allow you to block in a concept very quickly because they give you a very clear idea of the volume and you can manipulate the spheres like a skeleton by rotating around the joints (Fig.01). We could have started by creating the ZSpheres' skeleton in a pose, but we want to take advantage of editing the character symmetrically to work faster.

Fig.01

Fig.01

- Open ZBrush.
- Choose ZSphere from the Tool menu.
- Click and drag to create the ZSphere in the center of the screen. Press shift while dragging to make it perfectly horizontal.
- Press the Edit button at the top bar (or press T)
- Press S and reduce the Draw Size to 0.

This is a good procedure when working with ZSpheres, because the Draw Size will determine the area affected by your strokes and we will need to move nodes most of the time.

- Press X to activate Symmetry.

ZSpheres 2

When you put the cursor on top of the ZSphere, two little red circles will show up. That is where the new ZSpheres will grow from symmetrically (Fig.02). However, if you place the cursor at the center of the ZSphere a little green circle will show, meaning that a single ZSphere will grow from there as we are at the mirror plane.

Fig.02

Fig.02

- Click in the center (green cursor) on the top of the ZSphere and drag to create a new ZSphere.
- Change to Move mode (press W), click and drag on the new sphere to move it up. You can also scale the ZSphere by changing to Scale mode (press E) and dragging on the ZSphere.
- Now change to Draw mode (press Q) and repeat the same procedure to create a new ZSphere below the original ZSphere. We have just created the center of the body.

We will keep using this procedure to create a stick figure.

- Create new ZSpheres from the top ZSphere to create the shoulders and neck.
- Create new ZSpheres from the bottom ZSphere to create the origin of the legs.
- From the shoulders, neck and hip create the head, arms and legs (as in Fig.02).

ZSpheres 3

If you click in the middle of a chain of ZSpheres while in Draw mode, a new ZSphere will be created at that point. Let's use this to detail our skeleton. Keep changing the point of view to make sure that the ZSpheres are well positioned in space (Fig.03).

Fig.03

Fig.03

- Click in the middle of the leg to create the knee. Position and scale it.
- Do the same to create the elbow, wrist, chest and chin.
- Create a new ZSphere originating at the bottom of the leg to create the feet.

Now the main features are recognizable. Let's add a few more ZSpheres to those chains to create a bit of a natural curve in the arms and legs. You can press the A key anytime to view the Adaptive Skin mesh that will result from the ZSpheres. Press A again to go back to the ZSpheres.

Please have a look at Fig.03 to add the following ZSpheres:

- Add two more ZSpheres at the head area, one ZSphere at the neck, one ZSphere right below the shoulder to define the deltoids, one at the middle of the upper arm for the triceps, one at the forearm to define its shape. Add one more right below the wrist to give more detail to that area.
- Add one ZSphere at the thigh and two at the lower leg to define the calves. Also add one in the middle of the foot.

ZSpheres 4

We will now model the fingers.

- Click and drag on the ZSphere representing the hand to create the origin of the fingers and thumb. Make sure those ZSpheres are not too big, leaving some space between them.
- Click and drag on top of the origin of each finger and press Shift. This will create a ZSphere of the same size as the one in which you have clicked. Move the ZSpheres to represent the fingers as shown in the figure (Fig.04).

Fig.04

Fig.04

By adding a few more ZSpheres we will add density and correct the topology in some specific points.

- Create a new ZSphere originating at the chin. Press A to see the mesh. Notice that now we now have a higher mesh density at the chin.

ZSpheres 5

If you look at the lower back of the character and press A to see the Adaptive Skin, you will notice that the polygons of the waist are much bigger than the ones in the legs (Fig.05 - 06).

Fig.05

Fig.05

Fig.06

Fig.06

- Add a ZSphere at the back to add some more polygon density there.

At the front of the character we have an even bigger problem. Notice that the edge flow in the belly area is disturbed by a rhombus shape that prevents the existence of a continuous line at the center of the object.

- Add a ZSphere at the pelvis and this
problem gets fixed.

At the top and palm of the hand we can also find a geometric distribution that is very hard to sculpt.

- Add a ZSphere at the top of the hand and another at the palm. You will get a very high density mesh there, but it is better than the previous topological nightmare.

ZSpheres 6

The ZSphere base is ready.

- In the Tool menu, go to the Unified Skin pull down menu and click on Make Unified Skin.
- ZBrush will generate a new Tool starting with the prefix "Skin_".
- In this exercise we will not need the ZSpheres anymore, but if you want to keep them, press the Append button from the Subtool pull down menu and choose the new "Skin_" tool. Now you have the ZSpheres and Skin as Subtools of the same tool.
- Choose the "Skin_" Subtool and hide the ZSpheres Subtool (Fig.07).

Fig.07

Fig.07

Sculpting 1

I have decided to create a character without clothes on the upper part of the body in order to deal with anatomy issues and with wrinkled pants on the lower body to deal with cloth modeling (Fig.08).

Fig.08

Fig.08

Press the X key to activate Symmetry for the new "Skin_" Subtool. In the Geometry menu increase the number of subdivisions to 4 (when you create the skin, it already has 2 levels of subdivision).

- Select the Clay brush and start adding volume to the muscles. Use the Clay brush to add volume, the Shift key to smooth, and the Alt key to remove volume. Add the volume as if you were adding clay to a wire skeleton.

You can see that I have added a lot of volume near the feet as if the character was wearing bell bottom trousers. I have also added some clay at the trapezius muscles, deltoids, triceps and forearms. The back of the head was filled and some marks for the eye cavities, also the nose and jaw were added.

- To fix the hands, use the mPolish brush and rub it on the top of the hand and palm. Also use the Smooth brush. After reducing the volume, use the Clay brush to shape the volume. As the finger and palms are quite thin I would advise turning on the BackfaceMask button; you will find it in the Auto Masking section in the Brush menu. This will prevent the Clay brush from editing both sides of the finger at the same time.

Sculpting 2

- Subdivide the geometry twice more, increasing the total number of subdivisions to 6.
- Choose the ClayTubes brush and sculpt by applying strokes along the muscles following the muscle fibers. Use the Smooth brush to soften the forms (Fig.09 - 10). We can use this techniques for all the detailing, including the trousers.

Fig.09

Fig.09

Fig.10

Fig.10

Exporting to Topogun

If you wish to keep working without retopologizing you can do it, but the mesh distribution becomes uncomfortable to work with, and soon you will find you want your sculpting to flow in one direction while the mesh flows in another. I have chosen Topogun to retopologize, but you can use any other software, like ZBrush or 3ds Max (Fig.11).

Fig.11

Fig.11

In order to export the mesh to Topogun we will first decimate it to reduce the polygon count. You can download the Decimation Master plugin directly from Pixologic's web site.

- IMPORTANT: Save your tool before Decimation (If you wish to keep the decimated model save it in a different file).
- From the ZPlugin menu, click on Decimation Master and choose Pre-process Current. Wait for the calculations to be over.
- Choose a decimation percentage of about 10%.
- Click Decimate Current.
- From the Tool menu choose Export and save the model as OBJ.

Topogun 1

If you are not familiar with Topogun, it is software which has been specifically developed for retopology. It is much faster than any other similar software because it only has the necessary tools for the job and handles heavy models well. You can download a demo at www.topogun.com to give it a try (Fig.12).

Fig.12

Fig.12

The objective is to create a low poly mesh that will provide a good sculpting base, which means good edge flow and a denser mesh in the places where you will need to add finer detail (face and hands, for example).

One of the big advantages of Topogun is that the geometry you create sticks to the surface of your reference model.

- Open Topogun.
- Choose Load Reference from the File menu.
- Pick the OBJ we have exported from ZBrush.

To navigate, the commands are similar to Maya. Press Alt and drag one of the three mouse buttons to Orbit, Pan and Zoom.

We will be using two modes: Create and Edit. You can alternate between the two modes by pressing the right mouse button. Notice how the cursor changes between an arrow (Edit) and a cross hair (Create).

While in Create mode click on the surface to start creating a vertex on the surface. As you keep clicking you will create vertexes connected by edges. If three or four vertexes get connected by edges in a triangle or quad shape, a polygon is automatically created. When you want to close a shape or indicate that you want to share a vertex, press the Ctrl key while clicking on the vertex (you will notice that the vertex turns red).

If you want to move the vertexes around, just change to Edit mode and move them as it sticks to the surface. To add a vertex at an existing edge, press Shift while clicking at the edge.

Topogun 2

As the character is symmetrical, we will only retopologize half of the model.

IMPORTANT: While creating the vertexes at the center of the body (which is the mirror plane), select those vertexes in Edit mode and from the Modify menu choose ZeroX. This will place the vertexes at the zero X coordinate. It is the only way to guarantee that the vertexes are placed correctly at the center (Fig.13). I have created a keyboard shortcut for this function as it is used a lot (Edit > Keyboard Shortcuts).

- Create the polygons following the anatomical landmarks.
- Make sure to use the ZeroX function to keep the vertexes aligned at the center.

Check Fig.13 to see how the polygons respect the muscle structures. Also avoid creating triangles as quads will divide a lot better and create a more comfortable surface to work with.

Fig.13

Fig.13

Topogun 3

While creating the topology for the hands, I have opted to create four-sided fingers. In order for Topogun not to create polygons inside the fingers make sure that Reject Inner Faces, in the Options menu, is turned on.

Another good procedure, while working in detailed areas such as the hands, is to select one vertex in Edit mode and press the F key (stands for Focus). From this moment on, the view will orbit around the selected vertex. This is very handy when you want to work in a specific part of a model (Fig.14 - 15).

Fig.14

Fig.14

Fig.15

Fig.15

Use the same logic to create the topology for the lower body. Notice that I have left a small gap between the upper and lower body. This is because we will separate them later.

Topogun 4

- From the Select menu choose Select All Verts.
- From the Modify menu chose Create Symmetry. This operation might take a while.
- Select one vertex from the upper body and one from the lower body.
- From the Select menu choose Select Shell Border. All the vertexes at the border of each surface will be selected (Fig.16 - 17).
- As we don't want the mouth and waist to be welded, zoom in and while in Edit mode, press Ctrl and drag to deselect the mouth vertexes and the waist vertexes only leaving the vertexes at the center of the character.
- From the Modify menu, choose Merge with Closest Verts. Now the central vertexes are welded.
- From the File menu, choose Save Scene as.
- At the bottom of the window change the Save as type to OBJ
- Save it.

Fig.16

Fig.16

Fig.17

Fig.17

Import to ZBrush

- In ZBrush load the Tool with the character prior to the Decimation process.
- Select the character Subtool.
- In the Tool menu, under Subtool, click the Duplicate button.
- Keep the Subtool selected and press Import from the Tool menu.
- Choose the OBJ that was exported from Topogun.
- A window prompt will show up, press YES.
- The imported mesh will replace the selected
Subtool (Fig.18).

Fig.18

Fig.18

ZBrush Detail projection

- In the Tool menu, under Geometry, disable the Smt button next to the Subdivide button, so that when we subdivide the mesh it doesn't lose its volume.
- Press Divide until the subdivision level is increased to 4.
- Make sure that you are selecting the imported Subtool and that the only other Subtool that is visible is the detailed character.
- Click the Project All button in the Subtool menu.
- Hide the old detailed model.

Some minor projection artifacts might occur, as indicated in the image, but that is not a problem as we will be re-sculpting everything (Fig.19). You can delete the original Subtool and the ZSpheres. Keep only the new topology with the projected detail.

Fig.19

Fig.19

Polygroups

- In the Tool menu, under Polygroups, press Auto Groups. This will identify the upper and lower body as different polygroups (Fig.20).
- Select the Move brush.
- In the Brush menu, under AutoMasking, enable Topological.
- Pull the lower part of the upper body down with the Move brush so that it gets under the trousers. The trouser's polygons will not be moved due to the Topological masking.
- Turn the subdivisions down to the minimum level.
- Separate the mesh into the following polygroups: head, jaw, neck, shoulders, chest, upper arm, lower arm, hands, hip, upper leg, lower leg and feet. To do this isolate the polygons of each part of the model and use the Group Visible button to create each polygroup. Check Fig.19 to have a clear idea about their separation.

Fig.20

Fig.20

Posing

Use the polygroups to select the parts of the body that need to be moved and mask the non-moving parts (Fig.21). Change to Rotate mode. Click on the model and drag to create the Transpose tool. Click on the outer circles to reposition the Transpose tool and click on the inner circles to rotate the model. Typically, place one of the ends of the Transpose tool on the joint (for example the elbow) and move the other end to rotate around the joint. For more detail on this procedure, please check the second chapter of the first tutorial.

Fig.21

Fig.21

Transpose the model until you achieve the desired pose.

Detailing 1

Split the model by upper body, trousers and shoes.

- Change the model subdivisions to 1.
- Select the polygroup of the shoes and hide them.
- In the Subtool menu press Split Hidden.

The shoes are now a separate Subtool.

- Select the polygroups of the trousers and hide them.
- In the Subtool menu press Split Hidden.

The trousers are now a separate Subtool.

- Create some simple eyes in 3ds Max as in the first tutorial (a simple sphere with a recessed iris shape).
- Import and add them as a Subtool.
- Move, scale and rotate the eyes to put them in place. This is very important in order to correctly detail the area surrounding the eyes (Fig.22).

Fig.22

Fig.22

Detailing 2

To detail the muscles of the upper body I have used the Clay Tubes brush with the strokes following the muscle structure and then smoothing it with the Smooth brush (as described before). Some proportions were also continuously rectified with the Move brush; notice how the head gets flatter and wider, the shoulders have more mass and the neck is shorter and wider. The subdivisions value was increased to 6 to add the finer details (Fig.23).

Fig.23

Fig.23

To finalize I have used the mPolish brush to polish the chin, the forehead, the pectorals and most of the muscle groups in order to achieve a chiseled look. The veins were created with the Inflat brush.

Detailing 3

To create the nails I have used the following technique:

- Isolate the hand.
- While pressing Ctrl paint the nails mask on the fingers.
- Choose the Inflat brush and inflate the area where the nail grows from. Also inflate the remaining area surrounding the nail (Fig.24).
- Invert the Mask.
- Choose the Clay brush and fill the tip of the nail and apply progressively less clay until you reach the nail origin.
- Chose the mPolish brush to make the surface regular and remove any irregularities from the Clay brush.

Fig.24

Fig.24

The upper body is finished.

Boots 1

To start the boots, go to 3ds Max and create a simple boot shape, as in Fig.25.

Fig.25

Fig.25

The only thing to be aware of is you need to create some tight edge loops, increasing areas as I have at the border of the sole (yellow and orange material in the image), and where the boot meets the sole (green material meets gray material).

- Create a new MultiSubObject material with five Standard materials in it. Give a different diffuse color to each one (Fig.25).
- Apply the material to the boot.
- Define the material IDs on the boot's polygons in order to separate the parts that should have hard edges between them (as in the image).

Boots 2

- Select the boot object.
- In the File menu choose Export Selected.
- Choose OBJ format.
- Name it and click Save.
- In the OBJ Export Options menu change the Preset to ZBrush.
- Click Export.
- In ZBrush, go to the Preferences menu and enable the Import Mat as Groups in the Import Export submenu. This way the polygroups will be generated from the imported materials.
- Select the feet Subtool of the character (Fig.26).
- From the Tool menu chose Import and choose the boot OBJ file.

Fig.26

Fig.26

The boot is now imported, replacing the previous feet model.

Boots 3

- Position and Scale the boot of the left foot (Fig.27).
- Press Shift + F to see the Polyframe.
- Isolate each of the boot's parts by pressing Ctrl + Click on each polygroup.
- As you isolate each part, in the Tool menu, under Geometry, press the Crease button. This will prevent the borders of this part from being smoothed when subdivided.

Fig.27

Fig.27

Boots 4

- Also crease the polygons at the tip of the boot, as well as the polygon at the tip of the sole if you wish to create the typical tip of a Texan boot (Fig.28).
- Subdivide the Geometry up to 6.
- Use the Clay brush to add the wrinkles. Use the mPolish brush to flatten the wrinkles.
- If necessary, move the top of the boot to follow the lower leg and avoid intersecting the trousers.

Fig.28

Fig.28

Boots 5

To create the leather drawings on the boot we will use the Layer brush. The Layer brush has a nice feature: if you store a Morph target on the object before starting to use the Layer brush, the strokes will keep the same distance from the original surface even if you interrupt the stroke.

- Select the boot Subtool.
- In the Tool menu, under Morph Target, press StoreMT.
- Select the Layer brush and reduce the Z Intensity to 3.
- Paint on the surface to create the drawings.
- As we have stored the Morph Target, we can use the Morph brush to go back to the original surface. So use the Layer brush to create the drawings and the Morph brush to erase them (Fig.29).
- To create the stitches, I have selected the Stitch1 brush and changed the original alpha to one with simple stitches (check Fig.29) and painted them.

Fig.29

Fig.29

Boots 6

To create the other boot we are going to use another ZBrush plugin that can be downloaded from Pixologic - the Subtool Master.

- Select the boot Subtool.
- From the Zplugin menu choose Subtool Master.
- From the Subtool Master pallet choose Mirror.
- Enable Append as a new Subtool and press OK. This will take a while.
- Select the mirrored boot and position it according to the pose (Fig.30).

Fig.30

Fig.30

Trousers 1

If you examine photos of baggy jeans, you will notice that they are full of geometric shapes where the cloth is compressed, especially in triangular and rhombus shapes (Fig.31).

Fig.31

Fig.31

In the image I demonstrate the technique used to create the folds:

- Select the trousers Subtool.
- Increase the subdivisions to 7.
- Select the ClayTubes brush.
- Create the limits of the geometric shapes with the clay tubes.
- Use the same brush to fill the cavities inside the borders you have sculpted, creating ramped surfaces to define the planes.
- Choose the mPolish brush and the Smooth brush to polish the rough surface.

Trousers 2

In the image you can see how the sculpting of the trousers evolved (Fig.32). I've gone with a chiseled look so some of the folds are really sharp and exaggerated.

Fig.32

Fig.32

You can also notice that the character's pose and proportions have been refined; for that I have used the Move brush.

Trousers 3

I used the Stitch1 brush with several alphas for the jean stitches. In Fig.33 you can see the three alphas that were used: one stitch, two stitches, two stitches and a fold.

Fig.33

Fig.33

Conclusion

In Fig.34 you can see the character from different angles. This concludes the first chapter. In the following chapter we will deal with the UVs, textures and modeling of the belt in 3ds Max, and in the last chapter we will create the materials and lighting. See you in the next chapter!

Fig.34

Fig.34

To see more by Jose Alves da Silva, check out Digital Art Masters: Volume 9 and ZBrush Character Sculpting