Gesture represents the dynamic curve of the figure. In life drawing, these lines are quickly laid down on paper and do not necessarily seek to describe the contour or form of the figure at all (Figure 1.2). The function of the gesture drawing is to capture the rhythm and motion of the pose, the thrust of the figure, and the action inherent in its posture (Figure 1.3). Keeping a sketchbook of quick, loose sketches you don't intend to show is a great way to train yourself to find the gesture and rhythms in a figure. These kinds of exercises help sharpen your eye, and this translates into better figures when sculpting from the imagination.

Figure 1.1. Examples of traditional clay sculpture

Figure 1.2. A selection of gesture sketches

Gesture is the source of the life of a drawing or sculpture. It must be addressed from the outset—if the gesture is poor, it can be difficult to introduce it later into the process. If you start with a strong gesture, the sculpture will be appealing and alive from the start. A wooden, stiff pose with a poor gesture can have acceptable anatomical form and skin details while still being fundamentally unappealing (Figure 1.4).

The rules of gesture apply to even a sculpture that is not a figure. Notice in the lion's head how the gesture of the lines in the mane serve to create a sense of flowing action down toward the ring (Figure 1.5). These lines are more of a graphic consideration and can almost be considered in the abstract. Their presence serves to strengthen the visual impact.

Figure 1.3. An example of gesture and action

Figure 1.4. This Hercules from the Piazza della Signora in Florence, Italy, is an example of bad gesture in an otherwise good sculpture.

Figure 1.5. Lion head sculpture

Closely linked to gesture is the concept of rhythm. Master draughtsman George Bridgman describes rhythm as "in the balance of masses the subordination of the passive or inactive side to the more forceful and angular side in the action." That is to say, the interplay between the active and passive curves in the body combines to create a sense of rhythm in your sculpture (Figure 1.6).

Gesture is an important consideration no matter what you may be sculpting. It is gesture that makes a sculpture exciting, whether it is a door knocker, a monster, or a human. Especially when dealing with figurative sculpture, a well-executed gesture with special attention to rhythm helps establish a sense of weight and balance to the figure.

Figure 1.6. In this image of Celini's Perseus, I have indicated the alternating curves that establish a sense of rhythm down the length of the figure. Notice how they alternate, as in the inset image.

Although ZBrush excels at adding fine details to a model, form is always of primary concern when sculpting. Many sculptors rush to the detailing phase while overlooking the importance of developing the form, anatomy, and structure of the model. This makes for a weaker sculpture overall. Take Michelangelo's David, for instance; it's a perfect example of a masterful sculpture but there is not a single pore or wrinkle on the body. The figure lives and breathes because the interplay of forms of the surface gives the impression of skin, fat, and bone. David appears to be a living being in an inanimate material. This is true even when you are working on a completed 3D model from a third-party application. There is no replacement for the subtle variations in surface shadow and transitions you can add with ZBrush's sculpting tools. Adding a more organic sense of the artist in the work will create a far more appealing character. It may not seem like much, but taking away the perfect parametric nature of a polygon model can push a character's believability well into the next level before the first wrinkle or pore is applied.

Form in general refers to the external shape, appearance, and configuration of an object. In drawing and painting, you are describing form by directly applying light and shadow—from the highlight to the midtone to the core of the shadow. In sculpture, you are creating these halftones and value changes by altering the shadow casting surface. By altering the underlying shape, you can model the way light plays on the surface. Without shadow, there is no form. You can see this if you turn on Flat Render in the ZBrush window, thus removing all the shadows and highlights. Only a flat silhouette remains (see Figure 1.7).

Figure 1.7. Notice how when light and shadow are removed, only a silhouette remains.

It can be helpful when sculpting to remember that the shapes you are making with your brush will affect how light and shadow interact on the surface. That is how the shapes are created. If the light is turned off, all form goes away. Creating good form as you sculpt it requires an understanding of both the shape itself as well as the quality of the shadows created by that shape under different lighting conditions. As a further example of how shadow describes form, we can take a lesson from painting and drawing. Here is a photograph of a face next to the same photo posterized. With all the midtones removed so only the extreme highlights and shadows remain, you can still identify the fact that this is a face. When you're reading a surface, the shadows tell you everything about what you are looking at (Figure 1.8).

Figure 1.8. Even with just the shapes of the shadows, this face is still recognizable.

This gradient between the lightest light and darkest dark is called value. Paintings and drawings have what's called a key or value range—the set number of steps from lightest light to darkest dark found within the image. When you're sculpting, it is good practice to be sensitive to these gradations on the surface of your own work. Even though you are not applying value directly, you are affecting the values the eye perceives by the height of the shape you are sculpting or the depth of the recess. Examine how the shadows interact on the surface; to darken a shadow, you may deepen the crevasse or add to the mass of the adjacant shape. Moving the light often as you work can help you spot these value changes from different lighting conditions.

When you're dealing with form, it also becomes important to address transitions that create space between forms and how one feeds into another. Figure 1.9 shows how deepening a crevasse or raising a high point can darken your shadow and give it a harder edge. This will change the character of the transition.

Try to be sensitive to the transitions between your forms and the variation you create. If the transitions between all your shapes are the same hard edged shadows the figure will be visually bland.

Figure 1.9. By deepening the furrow next to the deltoid, the character of the shadow changes, changing the feeling of the transition. Notice how the relative darkness of the shadow changes from the clavicle to the arm in the first image. Also note how in the second image this value has now become one consistent value and thus less visually interesting.

An important concept to bear in mind while you sculpt is to reduce everything to its base form and work on big shapes first. Just as a painter will tackle the big shadows and big lights first, then work down to details, the same is true in sculpting. This is one of the most important aspects of this section to remember—by working on big shapes and then refining, not only do you ensure that you resolve the major shapes first, but it helps your mind organize the complex forms of the figure into easy-to-manage sections. The final result may appear complex and intricate, but you approached it in small portions one at a time (Figure 1.10).

Figure 1.10. These images show the progression of the lion head sculpture from the most basic, broad strokes down to the finer lines.

All forms can be broken down to their base shapes and planes. Complex shapes like the face mass can be reduced to aggregate planes for easier study and execution. This is called planar analysis. While sculpting you will find it helpful to always be thinking of what the basic forms are in your character and how they relate to one another (Figure 1.11). The viewer will have different reactions to a character based on the relationships between its basic forms. This relationship between forms is called proportion.

Figure 1.11. By reducing this creature to its most basic shapes, the form relationships and proportions become apparent.

The proportions between the basic forms have a visual impact on the viewer. These reactions can change based on how the artist manipulates these relationships. For example, a character with a huge, bulbous head on a small body will create a different reaction than one with a tiny head and an oversized body.

Proportion refers to the relationship between the overall size of an object and the relative sizes of its parts. Many books have been written on the balance of these measures, and the fundamental rules of proportion have been understood as far back as the ancient Egyptians.

When you're sculpting a figure, it is important to understand proportion as it pertains to the human form. Proportional canons are sets of rules to help guide artists in creating a specific type of figure.

There are many systems, or canons, of proportion. Michelangelo often used a heroic eight heads to measure the figure, while a more ordinary human measure is 7~HF heads high. No proportional system is "law," and there are variations in all people. These are intended as an idealized system of measure. Straying too far will result in a figure that looks "off."

By understanding the proportional canon you are working with, you can make educated decisions about the character you are creating by changing the proportion.

Use these guidelines as you sculpt:

Another Take: Gesture, Rhythm, Proportion

Featured Artist: Zack Petroc

You don't have to worry about gesture, rhythm, and proportion in all of your sculpts—only in the ones that you don't want to look lifeless.

Being aware of these foundational concepts, and what they can bring to your art, marks the first step down the endless path that leads toward perfecting your skills. I say endless because the more you learn about these concepts, the more you will realize just how complex and intricate their execution can be. To infuse your work with gesture and rhythm is to give it life, and to give it life is to create a work that can transcend its basic visual concept and become a true masterpiece.

No matter the subject—from animal, to human, to creature, to foliage—I always start by trying to understand its gesture and, more importantly, what its gesture is going to convey about the character. A powerful superhero archetype will have a distinctly different gesture than a cowering villain. There are countless conscious and subconscious gesture cues that give instant insight into the nature of your character. Hero types lead with their chest; from a side view, the character's chest is the farthest point forward on the figure. The head is typically pulled back creating a straighter line from the base of the skull to the upper area of the back where the neck inserts into the torso. By pulling the head back and pushing the chest forward, you are automatically creating a larger distance between the front and back of the arm. This allows our hero character to have wider shoulders and larger-than-life upper arms. It's the setup of the gesture, from the head to the chest, that allows all of these proportional cues to be possible. In this respect, the gesture truly is the foundation for our character to be built on.

Rhythm is linked directly with gesture and refers to the visual lines that flow through your character. Increasing your awareness of this concept is the first step toward mastering it. These rhythms are what lead your eye around the form and, when executed properly, convey a sense of movement and direction, even in a static sculpture.

Proportion is a relative thing. When I stand next to Hulk Hogan, my gigantic and, if you will, super-toned upper body might make him appear small. However, we all know that relative to the general public, this is not the case. He is indeed a large man. The same philosophy about relative size can be applied to individual parts that make up a character. For example, one way to make a character appear taller is to make its head smaller. Other, subtler cues to let our viewer know the innately taller stature of our character might be to widen the shoulders while keeping their overall mass smaller. We can also add a slight downward angle to the clavicle as it goes from the sternum to its end at the top of the shoulder. These cues are all taken from real-life proportions of extremely tall people and are therefore subconscious traits that can help convey the believability that our character is indeed tall.

Remember, mastering these concepts can take a lifetime, but becoming aware of them can happen as soon as you would like, and that's all it takes to begin the journey. (Well, that and a gnarly-looking old walking stick. Preferably one with some kind of killer animal head carved into the handle. I would suggest an Orca or some form of rogue badger. This will help get you there in style.)

In the following example, from my sculpting the female figure tutorial on Gnomonology.com, I've drawn black lines over the form to represent the gesture. These long, flowing curves are what the forms were developed around and help give the sculpture character. I typically start by visualizing these curves on screen while I sculpt, then try to push and pull the forms to match them.

In the next example, we can see the lines of rhythm that flow throughout the sculpture. Note their interaction as they overlap and traverse the form. Even in this somewhat standard pose, the rhythms should be visible and help to indicate a sense of movement.

Proportion plays a key role in defining the "character" of any design. The final image shows how enlarging the head on this sculpture affects the viewer's impression of it. The design appears more childlike, and seems to have a smaller overall stature. An important part of this exercise is to also be aware that none of the finite details were changed. This shows us just how secondary and inconsequential the finite surface details can be if we don't first establish the proper foundation.

ZBrush works with essentially three types of objects; models, tools, and documents. Models are geometry that you either create in ZBrush using Primitives and ZSpheres, or obj models imported from third-party applications like 3ds Max or Maya. These models can then become tools when you begin to subdivide and sculpt or paint on the surface. ZTools are a ZBrush file type for storing 3D models with multiple levels of subdivision as well as texture information. Documents are essentially images. Documents are a hybrid between painting and rendering. You can place your ZTools in the document space, light, shade, and render them as a 2.5D illustration.

The ZBrush workspace is called the document window. This is where we'll sculpt and paint our characters. The document window has many powerful and unique aspects that are often overlooked when you are not using ZBrush as a purely illustration or concept design tool.

The artist can "drop" tools in the document window, interactively lighting and shading them in 2D. You can even continue to sculpt on your illustration. Although many of the document-based tools are not useful to a production environment outside of the art department, I feel it is important to cover them here as they form the basis of ZBrush's toolset and influence how many of the tools and menus behave.

For the purposes of sculpting and painting characters, we typically do not use the document settings, but there are some cases where these tools will come in handy. Some brushes, especially those we use in the Projection Master plug-in, are document based, so it is important to understand the distinction between documents and tools as well as how to use them effectively together.

The purpose of this tutorial is to introduce you not only to sculpting in ZBrush but to the different methods of working in the program. While making this door knocker we'll be using primitives, the standard sculpting tools, alphas, and brush strokes. First we'll use ZBrush primitives to sculpt and assemble a door knocker.

Everyone uses the sculpting tools differently. You find the combination that works for you through experimentation and emulation. Sketching character heads or faces on primitive spheres and planes makes for great practice.

At this stage you can add another subdivision level to allow yourself more material to sculpt on. Continue to use the Standard, Inflate, and Clay brushes to define the head and mane. Notice that I am stroking in a general direction for the sculpted hair as I mass out its form (Figure 1.22).

At this point I begin to carve away the recess where the ring will fit into the lion's mouth (Figure 1.23, video time code: 00:20:25).

Figure 1.21. Pulling the snout forward from the top and side views

Figure 1.22. Progress shots

Figure 1.23. Sculpting a recessed area for the ring to sit

Now that the basic form of the lion is established, let's add the ring to his mouth. Adding the ring at this stage will allow us to sculpt the forms of his mane and mouth around the ring so it appears that the two parts are interacting.

Now that we have roughed in the lion head and placed a subtool, we can begin to refine the forms of the sculpture overall. In this section we'll continue to use the sculpting brushes to make the rough shapes relate to each other and create a sense of rhythm in the forms. Before we start, let's take a moment to look at some of the new tools and modifiers we'll use in this section, specifically the LazyMouse Pinch brush and BrushMod sliders.

The following list represents some of the edits to this sculpture to bring it to completion:

At this stage, the basic sculpture of the lion's head is complete, but so much more is possible here. If you would like to see how this sculpture is incorporated into a 2.5D illustration — with additional details like a backing plate and with the door textured and stained — please see the DVD for a PDF file which continues this project as an illustration (Figure 1.42). I encourage you to look at this material since ZBrush is a powerful illustration tool and many of its sculpting techniques are built on this foundation.

These techniques are useful to the digital illustrator as well as when conceptualizing a character with ZBrush. Even though you can export your work to external renderers for animation and rendering I wanted to show the power of ZBrush as a rendering and illustration tool in itself. These are often overlooked aspects of the program but they are powerful tools to have in your arsenal even if you never do 2.5D illustration. Many of these tools are usable on 3D models in edit mode using the Projection Master script. Projection master will allow us to blend 3D sculpting with the 2.5D tools to create highly detailed models for export to other applications. In Chapter 2 we'll look more in depth look at sculpting a bust in ZBrush.

Figure 1.42. The final 2.5D illustration created in the bonus section on the DVD. By sculpting the lion head knocker as a 3D object and combining it with canvas elements, a complex scene is created.