C h a p t e r D TE GH RI PY CO one RI TE MA AL
Blocking In the Mesh In this chapter we will create a sculpting mesh. This is a very simple blocked-in model to serve as a foundation on which to sculpt the figure. We will look at two different methods of creating a mesh upon which to sculpt our figure. The mesh we create will be a very basic armature, which represents the most basic proportions of the figure. The idea is to create the most versatile base possible to support the sculpting in subsequent chapters.
2 chapter 1 ■ Blocking In the Mesh The second section offers an interesting alternative to standard polygon modeling. This section is geared toward those users unfamiliar with traditional modeling or who may desire to learn a new approach. In this section we will create our base mesh using ZBrush exclusively, utilizing the mesh-generating tool known as ZSpheres.
■ Gesture, Form, and Proportion Gesture, Form, and Proportion When sculpting, I always try to consider three points as I work: gesture, form, and proportion. These three concepts are the foundation of my workflow. If each element is addressed in the sculpture, they combine to create a solid, effective sculpture. If any of these is omitted or addressed inadequately, the work as a whole suffers. Let us look in depth at what these three words mean.
4 chapter 1 ■ Blocking In the Mesh Figure 1.3 An example of gesture drawing Sculpture by Scott Spencer. Image courtesy anatomytools.com. Gesture is just as important in sculpting as it is in drawing. A figure without a clear gesture will seem stiff and dead. Even if it is a well thought out sculpture with accurate anatomy, if there is no gesture, the sculpture will fail to excite the viewer. Gesture is apparent even in a neutral pose.
■ Gesture, Form, and Proportion Gestural rhythms can be difficult to spot on the fully lit figure. For this reason, in Chapter 2 you’ll learn how to turn off surface shading in ZBrush and look just at the silhouette of the figure (Figure 1.8). When you look at the figure in outline, the gesture and rhythm comes into easier focus. By removing the distraction of interior forms, you can address the silhouette. This has a vast impact on the effectiveness of the rest of the figure. Figure 1.
6 chapter 1 ■ Blocking In the Mesh (a) (b) Figure 1.9 The rib cage: (a) basic forms, (b) the complete form Form and Light The perception of form is made possible only by the use of light and shadow. Figure 1.10 shows a figure (a) with no lights and (b) with lights. Notice that when light is off there is no form, only silhouette. It is helpful to understand that when you are sculpting, you are manipulating the effects of light and shadow on a surface.
■ Gesture, Form, and Proportion 7 Figure 1.11 Note that the shadow in this image was darkened by adding volume to the adjoining surfaces. The Interactive light button allows you to move the currently selected light with the mouse. Simply press the button and move the mouse, and the currently selected light will move around the sculpture. I usually set a hotkey for this tool by holding down the Control key and clicking the Interactive light button. ZBrush will ask you to assign a hotkey for the tool.
8 chapter 1 ■ Blocking In the Mesh In this book we use the eight-head canon. This means we will create a figure that can be evenly divided into eight head measures in height; that is, the head is 1/8 of the total. I chose this canon for several reasons. First, it is one of the easier to remember because the head measures fall on specific bony landmarks. Figure 1.12 illustrates another reason I chose this canon—the grace of the figure it produces.
■ Gesture, Form, and Proportion Once your figure is established you can manipulate proportions to change the perception of the character. See Figure 1.13 for examples of how subtle changes to the figure’s proportion can alter the character. Notice how simply lengthening the arms or enlarging the size of the head can vastly affect the perception of the character. Figure 1.
10 chapter 1 ■ Blocking In the Mesh Anatomical Terminology I will be using anatomical terms throughout the book where they are applicable. While it is beyond the scope of this book to offer an in-depth study of the physiology of the human body, it is important to have a basic understanding of anatomical terminology. Understanding anatomical terminology assists us in communication about the human form.
■ Anatomical Terminology Understanding names also helps identify the placement and function of a part. For example, if we know that distal means distant from the centerline of the body and head refers to the end of a bone, then when we read “the distal head of the humerus,” we know it refers to the end of the upper arm bone farthest from the shoulder. Many anatomical names have Latin or Greek roots, because the earliest anatomists named them using these ancient languages.
chapter 1 ■ Blocking In the Mesh Superior Po ste r ior Lateral Medial Anterior Inferior Figure 1.16 The directional planes Sculpture by Scott Spencer. Image courtesy anatomytools.com. 12 Figure 1.
■ Anatomical Terminology 13 Sculpture by Scott Spencer. Image courtesy anatomytools.com. Sculpture by Scott Spencer. Image courtesy anatomytools.com. As a rule of thumb, if a landmark is defined as being superior, you can infer there is a counterpart that is inferior. The same is true of posterior and anterior. Anatomical names for the bone landmarks can also influence the names of the associated muscles. Let’s look at the scapula. In Figure 1.
14 chapter 1 ■ Blocking In the Mesh When talking about muscles we will often refer to origins and insertions, as shown in Figure 1.22. The origin of a muscle is the point at which it originates on the skeleton. Muscles pull toward their origin. An easy way to determine the origin of any muscle is to find the point at which the muscle moves the least. For example, see Figure 1.23. The Pectoralis muscle originates on the sternum and inserts on the humerus or upper arm bone.
■ Creating a Base Sculpting Mesh 15 The muscles have these specific independent shapes even to the point of having defined angles and planes. Bear this in mind as we work since you want to avoid having a soft blobby figure at all costs. As we refine the muscle forms we will continually give attention to the planes and structural quality of each. This is part and parcel of being aware of the form in our sculpture. Creating a Base Sculpting Mesh We are now ready to begin creating our character.
16 chapter 1 ■ Blocking In the Mesh 2. Save your file. 3. Create a polygon cube by selecting Create → Polygon Primitives → Cube. Make sure Subdivisions Width, Height, and Depth are set to 1 so each side has only one face. Move this cube up so it lies between the planes marked 4 and 5. You will need to scale it down so the top vertices lie on the line marked 5. This cube will represent the pelvis of the figure, and we will extrude all other geometry from it (Figure 1.28). Figure 1.
■ Creating a Base Sculpting Mesh Figure 1.28 The first cube in front and perspective view 4. Keep the bottom of this cube aligned with the fourth head measure. This is the midline of the figure and is equivalent to the ischium or pubic bone of the skeleton (Figure 1.29). Select the top face and extrude up twice, ending at the shorter line between lines 7 and 6. This shorter line is one third of a head measure from the top.
■ Blocking In the Mesh Sculpture by Scott Spencer. Image courtesy anatomytools.com. chapter 1 Sculpture by Scott Spencer. Image courtesy anatomytools.com. 18 Figure 1.29 The skeletal ischium and the 4th head measure line Figure 1.30 The 1st rib and the 7th cervical vertebra Figure 1.31 Extruding and scaling the neck Figure 1.
■ Creating a Base Sculpting Mesh Figure 1.33 Marking menu sequence Figure 1.34 Cutting the centerline Figure 1.
20 chapter 1 ■ Blocking In the Mesh 8. Extrude the legs down by selecting the face pictured and extrude to the ground plane (Figure 1.36(a)). Repeat the extrusion in the area pictured in Figure 1.36(b). The two edges at the knee are important. The bottom edge at the second head measure represents an anatomical landmark called the tibial tuberosity (Figure 1.37). This is the bottom-most border of the perceived structure of the knee, although it is part of the shin bone.
■ Creating a Base Sculpting Mesh 9. At this point cut an edge along the side of the body. This will bisect the form from the side view as seen in Figure 1.38(a). Select the vertices of the leg from the knee down, and scale and move them back in the Z axis as shown in Figure 1.38(b). 10. To create the foot, arrange the existing edges so there are three faces toward the front of the foot, as shown in Figure 1.39(a).
22 chapter 1 ■ Blocking In the Mesh At this point we have the base geometry for the trunk and legs, but if we look at the figure in profile, you can see it is essentially a column (Figure 1.40). We will start now to edit the positions of the vertices in Z to start to suggest the profile of the figure. 1. Add edge loops and move the points only in the Z direction to start shaping the body (Figure 1.41). By selecting and moving points back, we can create the taper of the legs.
■ Creating a Base Sculpting Mesh 4. Adding the arms is as simple as selecting the face pictured in Figure 1.46. The placement of our vertices so far creates a convenient edge that will run from the bottom of the pectoral muscles in the front of the figure to the back of the armpit (also shown in Figure 1.46). We will extrude the arms out to the sides now but relax them a bit later in the sculpting phase.
24 chapter 1 ■ Blocking In the Mesh Figure 1.45 Distribute edges Figure 1.47 Arm span vs. height Figure 1.
■ Creating a Base Sculpting Mesh 25 Supination Image courtesy of www.3d.sk. Pronation Figure 1.48 The forearm muscles in pronation and supination 6. It is important to be sure the geometry is as clean as possible. If we export a mesh to ZBrush with holes or otherwise erroneous geometry that went unnoticed, it can be very difficult to fix once we have started sculpting. Use the custom polygon display to check for border edges and unmerged polygons.
26 chapter 1 ■ Blocking In the Mesh Figure 1.50 The Cleanup Options window Figure 1.51 The Average Vertices Options window We are now ready to export this model to ZBrush and begin sculpting. If you would rather jump right into sculpting, I have included this base mesh on the DVD, but I highly recommend following the process of building the model at least once. At this stage you are ready to move on to Chapter 2.
■ Creating a Base Sculpting Mesh ZSpheres have the benefit of being a fast and efficient method of creating your base mesh. They are easy to create, faster than polygon modeling, and they will automatically polygroup the model into logical sections. ZSpheres are also easier to re-pose and adjust than a polygon mesh in Maya. Things like fingers and toes are far easier to create with ZSphere chains than standard polygon extrusion.
28 chapter 1 ■ Blocking In the Mesh 2. With the tool loaded, go to Tool → Subtool and click the Append button. Select the ZSphere tool from the popup menu to append it as a subtool of the head measure guide. Make sure the ZSphere is the active subtool by clicking on it before you proceed. Also, make sure perspective is off by pressing the P hotkey. We will want to build this mesh in orthographic view. You will now have the eight-head measure guide loaded as a ZTool with a ZSphere as a subtool. 5.
■ Creating a Base Sculpting Mesh 29 Figure 1.55 The capsule mesh after moving the ZSpheres to the correct head measure lines 7. Under Tool → Adaptive Skin, turn on Classic Skinning. Set Density to 4, Ires to 3, Mbr to 91, and Mc to On. This insures the best results from the polygon skin. Feel free to experiment with these values and use anything that you feel makes your volumes better. The important thing in this tutorial is that the proportions remain consistent. 8.
30 chapter 1 ■ Blocking In the Mesh 10. Press the A key and check your progress. Your figure should look like Figure 1.58. 11. Add spheres for the elbows and knees so your figure looks like Figure 1.59. Make sure to place the knee ZSphere just above the 6th head line. Scale down the wrist and ankle ZSpheres slightly to give a taper to the limb. At this stage you may want to turn off visibility on the head measure subtool so you can see the fingers and toes as you work on them.
■ Creating a Base Sculpting Mesh 12. Create a ZSphere chain for the foot and heel (Figure 1.61). 13. To add fingers, draw five small child spheres on the end of the arm as seen in Figure 1.62. Figure 1.60 Click this icon to turn off visibility on the head measure subtool. (a) Figure 1.61 Creating a ZSphere chain for the foot and heel (b) Figure 1.
32 chapter 1 ■ Blocking In the Mesh 14. Move the thumb down and arrange the finger spheres in a natural position. Add another sphere to the end of each finger and pull them out. Remember, you can press Shift while dragging to make a new sphere the exact same size as its parent. Add a ZSphere to the wrist, and scale it down slightly so the arm tapers before the start of the hand. Press A to preview your mesh. Your hand should look like Figure 1.62b. 15. Repeat the same process for the toes (Figure 1.63).
■ Creating a Base Sculpting Mesh 33 These smaller spheres will create topology loops to represent the inner eyes and mouth as well as the nose and ears. If you preview this mesh, you will have something like Figure 1.66. The effect of these spheres differs from what you can do using Classic Skinning. Under Adaptive Skin enable Classic Skinning mode, set Ires to 3 and Mbr to 9. Move the eye and mouth spheres in slightly so they become holes in the ZSphere head (Figure 1.67).
34 chapter 1 ■ Blocking In the Mesh Figure 1.67 Adding spheres for the eyes, nose, ears, and mouth ZSphere2 Skinning Classic Skinning Figure 1.
■ Creating a Base Sculpting Mesh Classic Skinning ZSphere2 Skinning Figure 1.69 The facial topology seen under both skinning methods Figure 1.70 By adding more spheres to each limb, Classic Skinning can be made to more accurately represent the volumes of the figure.
36 chapter 1 ■ Blocking In the Mesh Figure 1.71 The final armature mesh Figure 1.72 With the Move brush the armature can quickly be refined into a human shape.
■ What’s Next? For more information about using ZSpheres, see ZBrush Character Creation. See the video for this lesson on the DVD for a complete walk-through of this process. This represents the most basic form on which to start sculpting. It doesn’t look special now, but it will be very useful to us since our base is built with accurate proportions in mind. ZSketching ZBrush also includes a new ZSphere based mesh tool called ZSketching.