Wiley ZBrush Digital Sculpting Human Anatomy
Contents
1. 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 By making a complex base mesh you can lock yourself into certain shapes too early By taking the approach we use here which creates an extremely simple blocked in model we will be able to sculpt nearly anything we want on the mesh If your ultimate needs demand more specific topology Chapter 9 deals with rebuilding the underlying mesh while retaining all your sculpted details This workflow of sculpting first and remeshing later is the standard approach that I have used professionally for the past several years for multiple clients The first section of this chapter addresses a standard polygon modeling approach to generating the mesh This takes place in Maya and assumes a certain familiarity with Maya s modeling tool set These tools and approaches are universal and can easily be applied to any polygon modeling package as the tools utilized are standard between all polygon modeling applications 2 CHAPTER 1 m Blocking In the Mesh The second section offers2. CHAPTER 1 m Blocking In the Mesh Lateral jedi Figure 1 16 The directional planes F M kad lt Sculpture by Scott Spencer Image courtesy anatomytools com Figure 1 17 The superior anterior iliac spine Anatomical Terminology 13 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 19 you see the back of the shoulder blade the posterior surface The landmark marked on the image is called the spine of the scapula This is an important landmark on the back of a fleshed figure Figure 1 20 The muscles that lie above and below this bone feature are named Supraspinatus and Infraspinatus respectively Figure 1 21 The names simply mean that the Supraspinatus is superior to or above the spine of the scapula and the Infraspinatus is inferior to or below it Again we see how the seemingly complex naming translates into very simple terms Once you understand anatomical direction you find many muscle names are extremely simple to remember based on this fact Sculpture by Scott Spencer Image courtesy anatomytools com Figure 1 19 The scapula Figure 1 20 The spine of the scapula is an important landmark on the back of a fleshed figure Sculpture by Scot
3. Control right click and select Edge Ring Utilities from the Marking menu From the second menu select To Edge Ring and Split using the Marking menus for split ting edge rings in Maya as shown in Figure 1 33 So we can mirror the model across the middle and cut a centerline down the model as seen in Figure 1 34 Using the Edit Mesh gt Insert Edge Loop tool insert a loop on either side of the center edge Figure 1 35 18 CHAPTER 1 m Blocking In the Mesh Sculpture by Scott Spencer Image courtesy anatomytools com Sculpture by Scott Spencer Image courtesy anatomytools com Figure 1 30 The 1st rib and the 7th Figure 1 29 The skeletal ischium and the 4th head measure line cervical vertebra Figure 1 31 Extruding and scaling Figure 1 32 Selecting an edge to form the neck the centerline m Creating a Base Sculpting Mesh 19 Figure 1 33 Marking menu sequence inse Loo Offset Edge Loop Tool Add Divisions plit Polygon To Loop Tool Slide Edge Tool Transform Component Flip Triangle Edge Poke Face Wedge Face Duplicate Face Detach Component Merge Merge To Center Collapse Merge Edge Tool Delete Edge Vertex Chamfer Vertex Click drag on edges Crease Tool Crease Sets Figure 1 34 Cutting the centerline Figure 1 35 Adding loops 20 CHAPTER 1 m Blocking In the Mesh 8 Extrude the legs down by selecting the face pictured and extrude to the ground plane Figure 1 36 a
4. more specific control over edge placement In our example this is apparent where the legs meet the torso In the Maya model we have the ability to create a more even transition of edges from the trunk into the legs while the ZBrush model simply splits into two legs extruded from the body Both will work fine for sculpting but as you start building more characters and sculpting in ZBrush you will discover the kind of base model you prefer to work with For this section we will use the head measure guide as a subtool to help us place the ZSpheres and create a figure in the correct general proportion Each line represents a head measure on an eight head tall figure The first set of lines represents the head itself Each mark down represents one more head measure The shorter line between the first and sec ond head measures marks the point of the shoulders on the figure 1 From the Tool menu load the measureguides zt1Z Tool We will use this model as a guide to help keep the figure s basic proportions in line Each line represents a head measure from the floor to eight heads tall The smaller line represents the level of the shoulders Figure 1 53 Shoulders Figure 1 53 The head measure guide tool iil 28 CHAPTER 1 m Blocking In the Mesh 2 With the tool loaded go to Tool gt 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
5. 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 I have included both models on the DVD and you are welcome to skip this chapter and move on to sculpting however I recommend building a base mesh using these methods at least once This is not so much for the technical experience but because this is the very first place in which we address the overall gross proportions of the human figure In the case of this book we will be using a proportion of eight heads high We will talk in more detail about proportions later in this chapter Sculpting the Figure In this chapter we will look at some of the core precepts that guide me while I sculpt any human figure Figure 1 1 shows the human figure that we will create in this book It is a heroic male figure realized in the eight head proportion which we will discuss in the next section It is my goal to share with you the workflows thought processes and technical approaches I take to sculpt this figure In this first chapter we will lay the groundwork for the remainder of the book In terms of creating the base mesh we will discuss the ideas of gesture form and proportion as well as ways of thinking about sculpting in a digital environment In terms of
6. is standing feet together palms out We will sculpt our character in a more relaxed pose but it is impor tant to understand that most anatomy books will refer to bones and muscles in this state When in this position anything toward the front of the body is called anterior while anything toward the back is called posterior The direction up is called superior while the direction down is called inferior Figure 1 16 shows how these and other directional terms are used in practice Let s look at an example of how the naming of a skeletal feature can clue us in to important information In Figure 1 17 you see the pelvis The marked bony landmark is an important measure on the figure it serves as the point from which the front leg muscles radiate It is called the iliac spine It is more specifically referred to as the superior anterior iliac spine This simply means that it is the superior toward the top anterior toward the front iliac spine Once you understand how this apparently abstruse terminology works the inherent meaning is quite simple By knowing this name we can also now infer that there must be a superior posterior iliac spine as well as inferior anterior and inferior posterior iliac spines Otherwise there would be no need to name one the iliac spine on top and in the front Figure 1 18 shows the posterior superior iliac spine which is also seen on the surface of the body making dim ples at the base of the spine 12
7. started sculpting Use the custom polygon display to check for border edges and unmerged polygons In Maya click Display gt Polygons gt Custom Polygon Display Make sure Border Edges is checked Figure 1 49 This will highlight any unmerged edges or holes in the mesh To resolve any other geometry problems use the Cleanup function found under the Polygons menu Cleanup will remove lamina faces and other problematic geom etry errors that may have cropped up while we model Figure 1 50 shows the Cleanup Options window Now delete the instance and duplicate again as a copy Merge the two halves and make sure all vertices along the edge are wielded Average the vertices by going to Mesh gt Average Vertices to display the window shown in Figure 1 51 This operation helps smooth the forms and soften any remaining facets C Al Yetces Display D Momas F Beckoling Highlight Crease vertices Veter Size 20000 Edges Standard Soft Harnd C Only hard Highight Border edges T Texture borders I Crease edges Edge width 5 5320 H Face Cenes D Nomas D Triangles Show item numbers Wertices D Edges l Face Mommas sizec po ry Uv Size hoon A Textuie coordnates D UW D UY bopokbgy Color Color in shaded display Figure 1 49 The Custom Polygon Display Options window I Non plenar Uve E Cleanup Options n S O Edit Help I Faces wih moe than 4 aides Concave faces Faces with holes D Norplant faces
8. thank him for permission to reference it here See the DVD for a video demonstration of this process This tutorial describes the key points but you will gain a much deeper under standing by watching the process in real time in addition to reading these steps While I rec ommend following along to better understand how landmarks are placed in space I have also included the final mesh on the DVD so you may move directly into sculpting in the next chapter See Figure 1 25 for an idea of just how simple the resulting mesh will be Figure 1 26 shows how even from a very simple base complex shapes can be sculpted with ease 1 Begin by loading your polygon modeling software In this case we will use Maya but the same simple steps apply to nearly all packages on the market From the DVD load the measurePlanes obj file This object consists of eight planes corresponding to each head measure Figure 1 27 This will guide us in placing major forms in the base model as well as making proportional decisions for the remainder of the project I have added the measure planes to a layer in Maya so I can show and hide them for clarity as we work The instructions in this procedure assume that like most ZBrush users you re also famil iar with Maya and basic polygon modeling techniques 16 CHAPTER 1 m Blocking In the Mesh 2 Save your file 3 Create a polygon cube by selecting Create gt Polygon Primitives gt Cube Make sure Subdivisions Wid
9. 65 Figure 1 63 Adding toes to the feet Figure 1 64 Adding the head and neck Figure 1 65 Adding spheres for the facial features 18 m 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 Now when you preview you will have recessed loops in the mesh for the eyes nose and mouth When adding geometry for facial features as we have just done this is where you must decide on which skinning method works best for you The default skinning in ZBrush ZSpheres2 will look much closer to the ZSphere chain you create for your figure but it will not handle the countersunk ZSpheres in a predictable manner That is one reason why there is a Classic Skinning button under the Adaptive Skin menu Experiment with both skinning methods For this tutorial I used Classic Skinning with the following settings l l Figure 1 66 The to make the edge loops for the facial features ZSpheres2 facial loops If you use the new ZSpheres2 skinning method make sure you do not countersink skinned the spheres for the facial features int
10. Remove Geometry M Lamina faces faces shating all edges W Nonmarifold geareby 1 Momak and geomety Geometry only ff Edges with zero length Length tolerance o cono70 ff Faces with zero geometry area Area tolerarcer o cono70 l Faces with zero map aiea Area blarance fm non fn l a ee a 26 CHAPTER 1 m Blocking In the Mesh Eh Average Vertices Options Oe Edit Help Description Smoolhs the mesh by moving verlices Does mot nceace the number of polwgone inthe mesh Setting Smoothing amaurk i _ 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 However if you prefer to generate your base mesh in ZBrush the following section illustrates this process using the ZBrush mesh generating tool known as ZSpheres Building a Sculpt Mesh in ZBrush In this section we will look at a method of starting your sculpt mesh entirely in ZBrush using its powerful polygon model generation tool called the ZSphere Instead of mov Figure 1 52 An example of a ZSphere model ing points and edges in space as one would do in Maya or other 3D applications in ZBrush meshes are buil
11. 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 repre sents 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 We will talk more about the knee in Chapter 6 Figure 1 37 The tibial tuberosity on the skeleton and overlay m Creating a Base Sculpting Mesh 21 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 This configuration will allow us to extrude five toes from the minimal number of edges and is a technique I learned from Zack Petroc Select these three faces and extrude them forward as shown in Figure 1 39 b See the chapter video for an in depth look at this process Figure 1 38 a Adding edges b moving verts Figure 1 39 a Foot faces b extruding the foot 22 CHAPTER 1 m 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 star
12. culpting silhouettes planes and plane breaks By look ing at the figure in terms of its external profiles we can establish important landmarks without being distracted by too much detail too early We can also take this opportunity to strengthen the gesture and rhythm of our figure
13. daptive Skin separately We will now generate a polygon mesh from the ZSphere model Under the Adaptive Skin menu click the Make Adaptive Skin button You will notice a new ZTool listed in the tool menu prefixed with the name Skin Select this tool This is the polygon mesh generated from the ZSphere model Save this tool separately from the ZSphere model in case you want to revisit the original ZSphere chain for further edits in the future By using the Move brush you can quickly move the mesh into a more accurate shape of a basic human as seen in Figure 1 71 Notice the eyes and mouth have been pressed in and the hands and feet shaped This is done entirely with the Move brush to help refine the figure for the next chapter The very simple Zsphere model can quickly be refined into a more accurate human form using the Move brush alone Figure 1 72 Please see the DVD for copies of all the ZSphere and Adaptive Skin models as well as multiple variants of the ZSphere skeleton 34 CHAPTER 1 m Blocking In the Mesh ZSphere2 Skinning Classic Skinning gt Figure 1 68 The two skinning methods Zspheres2 and Classic Creating a Base Sculpting Mesh 35 Classic Skinning ZSphere2 Skinning 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 m Blocking In the Mesh Figure 1 71 The final armature mesh Figure 1 72 With the Move br
14. e 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 ona surface This is different than paint ing where you are creating light and shadow by directly applying them to the surface Figure 1 11 shows how a shape can be changed and the resulting highlight and shadow are altered as well This is particularly important in the final stages of a sculpture when you are refining the surface quality the nuances of fat muscle skin and bone Often it is helpful in remaining subtle in your approach if you remember that at this stage you are catching light and casting shadow more than you are adding materials or carving away Moving your light can also illustrate the transitions between forms Figure 1 11 shows two different transitions between the same shapes Notice the difference between them While they may be subtle little details like this can add up to a great character sculpture Because of the importance of light and shadow to the subject of form you will want to be able to move your light as you work There is a handy utility for this built into the ZBrush interface This tool is found under ZPlugin gt Misc Utilities and is called Interactive Light Figure 1 10 Form and light m Gesture Form and Proportion 7 Figure 1 11 Note that the shadow in this image was darkened by addin
15. e 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 This will keep the fig ure ina neutral pose but also allow us to add some gesture and spring to the arms An important thing to note The arm span on a eight head figure is equal to the height Figure 1 47 Figure 1 43 Deleting the loops 5 The arms are built in the anatomically neutral position knows as supination An easy way to remember this position is the way you position your arm to hold a bowl of soup In this position the flexors and extensors of the forearm are relatively straight as opposed to their position when rotated Figure 1 48 In this phase I extrude the fingers and toes taking care to place edges at each knuckle This process is best shown on screen rather than described in text I encourage you to watch the accompany Figure 1 44 Drawing new edges at crotch ing video to see this in action 24 CHAPTER 1 m Blocking In the Mesh Figure 1 47 Arm span vs height m Creating a Base Sculpting Mesh 25 Supination Pronation Figure 1 48 The forearm muscles in pronation and supination Image courtesy of ww 3d sk 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
16. eating our character To start we will block in a polygon mesh in the proper proportion This is a very simple block mesh which will serve as a base for all our sculpting Later in this book we will look at methods of reto pologizing this mesh for film or games as an animation ready mesh For now we are only concerned with sculpting and cre ating a base suitable to support the forms we want to create A sculpting mesh differs from an animation mesh in that the topology is not laid out for animation Instead a sculpt mesh features evenly spaced efficient polygon edges that allow for consistent subdivision in ZBrush without allowing the base mesh to define any form on its own The only aspects we want the sculpt mesh to address are gesture and proportion This mesh is purely for sculpting It is not an animation ready mesh as seen in Figure 1 24 I find that starting from the most basic mesh allows me the most freedom in sculpting Figure 1 24 An animation mesh is prepared with Sometimes if you have a muscle form edge looped in your edge loops and topology that facilitates UV layout base model it can fight you as you sculpt and animation Building a Sculpt Mesh in Maya In this section we will create our simple base sculpt mesh using very simple polygon model ing techniques that are applicable to nearly every modeling package on the market as well as Maya This simple base mesh layout is based on a modeling approach used by Zack Petroc I
17. ed The final tenet proportion insures that the fig ure looks realistic within a generally acceptable set of rules for its relative size If you have good gesture and form but proportion is tweaked your work will not look wrong but styl ized To create the sense of a shorter figure you may adjust the proportions of the head and hands to the body for instance If the gesture and form are correct proportion is a visual guide to the size and sometimes the character of the figure 9 HT 10 CHAPTER 1 m 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 By understand ing what the names are and mean we can decipher valuable information from other sources like textbooks and anatomical reference materials Figure 1 14 shows the figure with skin and fat removed revealing the major muscle groups we will be looking at in this book Figure 1 14 The figure with its underlying anatomy revealed m Anatomical Terminology 11 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
18. 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 In modern times it has the added benefit that two doctors of any nationality with different languages can refer to the same part and be understood They may look complex but the words have very simple meanings Once you under stand these meanings you will be able to decipher a wealth of information The reason I give most often for why it s valuable to learn the names of parts is that it gives you a kind of mental box in which to put informa tion about a part If I know the name of a muscle it is easier to remember its placement shape and function Without the name of the muscle you are dealing with a volume of information about some abstract shape Again I should also stress that names often carry hints to placement and function in them There are some standard anatomical direc tions movements and regions that we will look at first What follows is a selection of some of the more commonly encountered These names may seem daunting at first but just become familiar with them You will find them used over and over when describ Figure 1 15 The default position ing different muscles and bones Figure 1 15 shows the human body in the default anatomical position That
19. g 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 I use Interactive light often as I work and I encourage you to do so as well As you sculpt take time to move the light and see how different lighting conditions change your perception of the shapes you are making By observing the highlights and shadows on the figure from different lighting conditions you can build a more complete picture of the shape in your mind This will be invaluable for picking out areas that may need more work which may have been missed otherwise By doing this you will ensure the sculpture is accurate under all lighting conditions Be aware that interactive light only works with the Standard Materials and will not function when using Matcap Materials Proportion Proportion refers to relative sizes between parts There are several systems of proportion for dealing with the human figure All of these systems known as canons strive to create a gen eral set of rules that help create a natural looking figure In reality no canon of proportion is always correct for all people The importance of the canon is that it provide
20. gure 1 62 Figure 1 60 Click Figure 1 61 Creating a ZSphere chain for the foot and heel this icon to turn off visibility on the head measure subtool Figure 1 62 a Adding the fingers b the fingers in place HT 32 CHAPTER 1 m Blocking In the Mesh 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 Adda 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 Repeat the same process for the toes Figure 1 63 The shape may look strange now but the odd forms can be corrected in seconds with the Move brush once we start sculpting In addition it is far easier to pose and create gesture in the figures using ZSpheres than it is when extruding faces in Maya Now we want to add the head and neck Restore the visibility on the measure guides Turn on transparency and from the top view add a neck ZSphere on the shoulders Draw another ZSphere on the neck and move it up to the first head measure as shown in Figure 1 64 At this stage add two ZSpheres between the head and shoulders by clicking between them Scale these two spheres down to create a neck Add small spheres for the eyes nose and mouth as seen in Figure 1
21. he first sphere If you press Shift while drawing the sphere will become the same size as the original Rotate to the top view and repeat the process Figure 1 54 6 Press the A key to preview the mesh Your mesh should look like Figure 1 55 Press A again to exit preview mode and move the bottom sphere to the 4th head measure line and the top sphere to the shoulder line as seen in Figure 1 56 If you have problems seeing the head measure lines turn off transparency so they become opaque again Figure 1 54 The initial ZSphere chain m 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 gt 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 Add child spheres for the shoulders and pelvis as seen in Figure 1 56 Be sure to check your progress with the A key Since we are using the new ZSpheres2 skinning by default the mesh should conform exactly to the spheres you see on screen 9 Draw ZSpheres for the hands feet and head Switch to move mode with the W key and pull them away from the body Figure 1 57 Drag the foot spheres down to the 8th head measure Drag the wrist
22. is the active subtool by clicking on it before you pro ceed 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 Move the ZSphere so it lies on the 3rd head measure You can move the ZSphere by pressing the W hotkey to enter move mode or by selecting Move from the top of the screen You will also want to scale the ZSphere down so it is about the size of one head unit or the spaces between the lines on the head measure guide Scaling is preformed by selecting Scale from the top of the screen or pressing the E hotkey Make sure you are in draw mode by pressing the Q key or selecting Draw from the top of the screen Press the X key to enter X symmetry mode This will turn your cursor into two green dots You know you are centered on the ZSphere when the two dots become one Rotate to the bottom view of the ZSphere You will need to enable transparency on the right side of the screen to see through the head measures to the ZSphere As of ZBrush 3 5 you can adjust the transparency effect by going to Preferences gt Draw and turning off GhostClearIransparency There are also several sliders here that can further refine the transparency effect to your liking Make sure your two dots join into one on the surface of the ZSphere and draw a new ZSphere on the bottom of the floor by click dragging on t
23. lustrates another reason I chose this canon the grace of the figure it produces Compared to a 7 head figure the eight head model is longer and more graceful The 7 head figure although it s more accurate can have the appearance of being somewhat dumpy An eight head figure gains length in the legs and arms and can lead to a more graceful and heroic looking figure Remember that canons are sets of rules to help you create a figure that looks right once you understand these rules you can break them But at the outset it is important to have a set of guidelines like this to help keep the figure within acceptable ranges of propor tion This assists you in trying to find areas that may not be working and determine why not Being able to refer to your canon of proportion and correct the figure based on that is a better approach than simply tugging at the overall proportion until it looks right In the eight head canon measures fall on the following points Landmark Head Measure Chin Head 1 Nipples Head 2 Navel Head 3 Pubic bone Head 4 Lower thigh Head 5 Bony protrusion of the knee Tibial tuberosity Head 6 Lower shin Head 7 Bottom of feet Head 8 Figure 1 12 The eight head canon Gesture Form and Proportion Once your figure is established you can manipulate proportions to change the percep tion of the character See Figure 1 13 for examples of how subtle changes to the figure s proportion can alter the characte
24. o the head ZSpheres2 does not support coun tersink and this may cause undesirable behavior Figure 1 68 shows this ZSphere model under both skinning methods in ZBrush Classic and ZSpheres2 Notice that the Classic Skinning gives you more accurate facial loops for sculpting the eyes nose and mouth while the default ZSpheres2 skinning seen on the left follows the ZSphere chain more accurately but does not recess the topology for the face The edge loops are still there in ZSpheres2 you will just have to manu ally press them into the head when you start sculpting Both skins will work fine it is entirely up to your own preference when working with the base mesh Figure 1 69 shows the facial topology of Classic Skinning and ZSpheres2 so you can see how the underlying loops are conformed to the surface Remember if you use Classic Skinning the volume of the limbs will no longer follow the ZSphere chain as you have made it To rectify this simply add more Zspheres between the joints to help define the forms as seen in Figure 1 70 It is also important to note that the hands and feet will generate topology differently between the two skinning methods Try both and decide which mesh is more appealing to you as a base on which to sculpt Please see the DVD for a video demonstrating both ZSphere approaches and the nuances of each skinning method Save your Zsphere model by clicking Tool gt Save As make sure to save the Zsphere model as well as the A
25. r Notice how simply lengthening the arms or enlarging the size of the head can vastly affect the perception of the character Figure 1 13 Proportion and character versions From Basic Forms to Complex Shapes How do we apply the tenets of gesture form and proportion to sculpting First we will establish the figure gesture within a set of proportions in this case eight heads Then we move on to each part of the body each time readdressing the gesture forms and propor tions of the figure in relation to the whole By carefully considering each as we progress through the character sculpture we can ensure that we stay on track and sculpt with direction not mindlessly moving digital clay in the hopes it will look right In this section we will look at some of the approaches we will take in developing this character sculpture We will look at each part of the figure from the most basic aspects down to the more complex sequentially creating a more and more realized form By establishing the most basic shapes first we will make the final figure all the more realistic because the details live on a shape that is solid and feels accurate Ultimately I consider gesture the most important aspect of making a sculpture or drawing feel compelling Without it the figure is still and less than lifelike Gesture is fol lowed closely by form the effective representation of a shape in space Bad form creates anatomy that looks mushy and ill defin
26. rface shading in ZBrush and look just at the sil houette 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 7 Curves in a skeleton leg and Figure 1 8 The whole figure in silhouette shaded a fleshed leg in silhouette Form Form is the external shape of an object Form is represented by light and shadow and the gradients between There is a hierarchy of form 1 Primary form 2 Secondary form 3 Tertiary form Throughout this book as we address different parts of the body we will break com plex shapes down into their simpler parts By dissecting them into basic forms we render them easier to understand and reproduce For example let s look ahead to the rib cage By breaking it down into a simple egg and slicing off planes we come to the more subtle com plex form of the rib cage Figure 1 9 This approach allows us to recognize and address changes in planes and nuances in form that we might otherwise overlook when trying to sculpt a finely detailed rib cage from the start 5 6 CHAPTER 1 m Blocking In the Mesh 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 figur
27. rts of a muscle As we discuss each part of the body in this book we will be looking at the major muscle forms including their origins and insertions It s important to under stand what these terms mean and how they apply so as we come across them later you will understand their importance A simple way to remember the difference between origins and insertions is that a muscle pulls in the direction of its origin One last point I want to mention here about muscles As we start sculpting I will often refer to planes and plane breaks This is simply a way to define a structure and apply an angular quality to the surface of the figure For years I considered the muscles to be somewhat soft forms inside the body pressed against each other It wasn t until I started doing cadaver dis section that it came to my attention that the muscles are very structural bodies that maintain their shapes independent of each other Figure 1 23 Pectoralis origin and insertion m 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 cr
28. s the artist with a standard set of measurements to keep the figure looking natural View Blur When working on the figure it can be useful to look at the surface in terms of shadow shape and value By value mean the relative lightness or darkness of the shadow When working with traditional media for centuries artists have used the trick of squinting at the model to reduce the amount of visual information into a fuzzy generalized image This helps you judge the shadow shapes and form ZBrush has a feature built in to help you replicate this effect It is called View Blur View Blur is located under the Preferences gt Draw menu Simply set the slider to a value above 0 and press the VBlur but ton This will apply a Gaussian blur to the entire canvas helping you pick out the general shape of the forms and the patterns of highlight and shadow on the surface With the view blurred it is often easier to find shadows that are too dark or too hard or areas where the highlight appears wrong This is a telltale sign that something is wrong with the sculpture in this area 8 CHAPTER 1 m 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 il
29. spheres to just below the 4th head measure Once the wrists are placed at the point just below the waist we know the arm length is accurate Switch to rotate mode with the R hotkey and clicking between the shoulder and wrist spheres rotate the arms up as seen in Figure 1 57b This is because the arm span is equal to the total height of the figure If we place the wrist just below the waist then rotate them up into position we can be sure the arms are the correct length once the hands are added Figure 1 56 Creating the shoulders and pelvis HT 30 CHAPTER 1 m 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 Visibility is disabled by clicking the eyeball icon next to the subtool in the Subtool menu Figure 1 60 Figure 1 57 Stretched arms and legs Figure 1 58 Figure preview Figure 1 59 Adding spheres for the elbows and knees m Creating a Base Sculpting Mesh 31 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 Fi
30. t Spencer Image courtesy anatomytools com 14 CHAPTER 1 m Blocking In the Mesh When talking about muscles we will often refer to origins and insertions as shown in Pistre 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 origi nates on the sternum and inserts on the humerus or upper arm bone The head that attaches to the arm has the most range of motion so it is the insertion The shape of a muscle may change as it moves but the origin and insertion never change they are attached to the skeleton So by knowing these points you understand how to place the muscle in any pose You also know what direction the muscle pulls in and what its function is If you know the start and end points of a muscle deciphering its function is rather simple Just remember that muscles pull toward the origin and you will quickly realize the purpose of the muscle in question Combine this with useful clues contained in the muscle name and you have a wealth of information about the form in question DP od ba IN AE G Pa _ _ 5 i ee cy cj p 2 4 e PE HE Ww d A a N a A f ai fi F f E 7 f E NA fj A i simiq f 4 bi i LATON Figure 1 21 The supra and infra spinatus muscles Figure 1 22 The pa
31. t by creating and connecting spherical volumes Figure 1 52 For more information on ZSphere modeling please see my ZBrush Character Creation Advanced Digital Sculpting Sybex 2008 ZSpheres in ZBrush 3 5 has been vastly improved from previous versions There have been some significant changes in the way ZBrush calculates the skin from your ZSphere model While the new version called ZSpheres2 creates a model more accurate to the shape of your ZSphere chain the original skinning method is still included in ZBrush 3 5 since it is still more effective for some applications like making topology loops for eyes and mouths We will look at how to create both types of skins in this section examining their relative strengths To help us place the masses and maintain accurate proportions we will use the head measure guide ZTool included on the DVD To load this into ZBrush follow the demonstration video of this process also on the DVD m Creating a Base Sculpting Mesh 27 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 The drawback to ZSpheres is that they can be limiting when you are trying to exert
32. t 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 At this stage also note the S curves and alternating rhythms of the body which are starting to take shape To see this process in full be sure to watch the accompanying DVD 2 We will now add a loop in the crotch area By adding this in the geometry it helps us define the tricky transition from the legs into the pelvis later on as we sculpt This is the simplest approach and allows the most freedom later down the line Cut two edges at the pelvis as seen in Figure 1 42 Delete the loops shown in Figure 1 43 Now draw a connecting edge to allow the faces at the centerline of the body to turn Figure 1 44 3 At this point even out the edges to continue to define the volumes of the body Figure 1 45 The idea is to use the least number of edges possible to define shapes and volumes More edges now means fewer subdivisions later in ZBrush Figure 1 40 The figure as a column Figure 1 41 Shaping the body in profile m Creating a Base Sculpting Mesh 23 4 Adding the arms is as simple as select ing 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 figur
33. t sculpture with accurate anatomy if there is no gesture the sculpture will fail to excite the viewer Gesture is appar ent even in a neutral pose The bones of the body have a gesture that telegraphs out to the final fleshed figure Without this gestural quality characters would appear to be composed of tubes with no overall rhythm Closely linked to the idea of gesture is rhythm Rhythm refers to the alternating curves or shapes present in the figure Figure 1 4 shows how rhythm can be seen in the alternating masses of the head chest and pelvis Notice how the masses are offset and rotated against each other to create the alternating flow of mass distribution Figure 1 5 shows the rhythm in the curves of the skeleton Notice how each level from the most basic representation to the most complex echoes the same general rhythm These rhythms that are present in the skeleton influence the muscle forms and finally telegraph out into the final fleshed figure Figure 1 6 Notice the rhythmic curves of the skeleton leg and how they are echoed in the final fleshed leg in Figure 1 7 Sculpture by Scott Spencer Image courtesy anatomytools com Figure 1 4 Rhythm expressed in the Figure 1 5 The rhythm of Figure 1 6 Rhythm in silhouette alternating of masses curves visible in a skeleton m 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 su
34. th 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 25 The final base mesh Figure 1 26 This image illustrates how much form can be sculpted from the simplest base mesh Figure 1 27 Measure planes m Creating a Base Sculpting Mesh 17 Figure 1 28 The first cube in front and perspective view 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 This is the highest point of the neck on the back of the figure corresponding to the 7th cervical vertebra and on the front of the figure to the first rib These can be seen in Figure 1 30 Scale down this last extrusion This will be the start of the neck As shown in Figure 1 31 extrude this face up to the bottom of the first head measure and then again to the top This will represent the neck and head of the figure We will now cut a centerline for the body Select one of the edges running lengthwise down the body Figure 1 32
35. the tutorial itself we will be creating the very basic sculpting blocked in mesh that will be the foundation of the next several chapters In this first chapter we will be addressing the overall proportion of the human figure as well as starting to think about how to create a mesh that is in line with our chosen proportional canon Figure 1 1 The final figure Gesture Form and Proportion 3 Gesture Form and Proportion When sculpting I always try to consider three points as I work gesture form and propor tion 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 omit ted or addressed inadequately the work as a whole suffers Let us look in depth at what these three words mean Gesture Gesture is the overall dynamic curve or action line that can be traced through a figure Figure 1 2 shows the gesture line superimposed on a sculpture A gesture drawing is one that does not attempt to describe the outline of the figure but the energy or direction of the action Figure 1 3 shows an example of gesture drawings A Figure 1 2 The gesture line superimposed on a sculpture 4 CHAPTER 1 m Blocking In the Mesh Figure 1 3 An example of gesture drawing 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 ou
36. ush the armature can quickly be refined into a human shape m What s Next 37 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 While this is a unique and powerful tool for generating models with a medium level of surface form quickly do not use it in this chapter to generate the sculpting model This is because the tool is stroke based and lends itself to a more involved process of building up muscle forms with strokes rather than generating a quick and simple gesture figure ZSketching also requires you take extra steps to generate an Adaptive Skin with multiple subdivision levels feel that we will learn more in the next two sections by sculpting our shapes directly in the simple block in mesh ZSpheres and Polygons lend themselves to forcing you to think in very simple global terms about the overall gesture and proportion of the figure If you would like to take a more stroke based approach to creating an ecorche base mesh recommend checking out the videos on ZSketching available from www pixologic com What s Next In the next chapter we will discuss s
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