Anatomy of the Face for Artists Volume 1: Sculpting the Skull
Anatomy of the Human Face
by Ryan Kingslien with Nicholas Breslow
by Ryan Kingslien
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YOUSCULPT
Anatomy of the Face for Artists Volume 1: Sculpting the Skull
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Cover design by Ryan Kingslien Book design by Ryan Kingslien and Nicholas Breslow Compiled by Nicholas Berslow from a ZBrushWorkshop’s Lecture Development Editing by Nicholas Breslow Production Editing by Sonia Prasad Copyright © 2011 by Ryan Kingslien All rights reserved. No part of this book may be reproduced in any form or by any electronic or mechanical means including information storage and retrieval systems, without permission in writing from the author. The only exception is by a reviewer, who may quote short excerpts in a review. Ryan Kingslien Visit my website at www.ZBrushWorkshops.com
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Acknowledgements Sculpting the face is one of the hardest things to do.
Its unyieldingly frustrating but its always an amazing challenge. What little understanding I have of the face has its origins in my time with Al Gury, chair of the Painting Department at PAFA. As always, Ofer Alon and Jaime Labelle continue to be guiding lights in their work with ZBrush and bringing digital sculpting to the masses. Also, this book would not be possible without the support and hard work of my wife Sonia Kingslien I would like to call special attention out to Nicholas Breslow who compiled the bulk of this document from one of my workshops at ZBrushWorkshops. He did a fantastic and thorough job.
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About the Author Ryan Kingslien is the founder of www.ZBrushWorkshops.com.
He attended the Pennsylvania Academy of Fine Art and the Gnomon School of Visual Effects. He was the first product manager for ZBrush at Pixologic, where he combined the efforts of programmers and artists to help create some of the revolutionary tools in ZBrush. He also created the first industry-standard curriculum and documentation that helped bring ZBrush to companies such as Industrial Light & Magic (ILM), Sony Pictures Imageworks, and Electronic Arts (EA).
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Table of Contents The Beginnings Overview
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Landmarks
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Skull: Proportions
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Mapping the Proportions of the Skull 9 Skull: Basic Shape Skull: Facial Grid
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Using Transpose as a Measuring Tool 20 Mapping the Facial Grid Using PolyPaint Skull: Sculpting the Facial Grid 23
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Skull: Cranial Block-in 26 Skull: Detours on Way to Orbit of Eye 31 Detour #1: Supraorbital Margin and Infraorbital Margin Detour #2: Planes of the Orbit of the Eye
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Skull: Four Quadrants of the Inside Corner of the eye Skull: Defining the Maxilla 38 Skull: Defining the Upper Brow
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Skull: Frontosphenoidal Process of the Zygomatic 44 Skull: Defining the Back of the Skull 46 Skull: Corrections
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Skull: Defining the Mandible 52 Sculpting the Teeth Plate, (Alveolar) 55 Refining the Jaw
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Reference Check
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Sculpting the Teeth
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Mapping the Teeth Using PolyPaint 60 Creating Teeth 62 Molar Template 63 Positioning Teeth
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Refining Individual Teeth Mirroring Teeth
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Mandible Refinement to Accommodate the Teeth 67 Final Progress Check 68 6
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The Beginnings Overview Welcome to the Anatomy of the Face Volume 1, The Skull. The goal of this book is to be a companion to the workshop at ZBrushWorkshops that goes by the same name. However, it can also be enjoyed separately is contains almost all of the steps the workshops does. The layout of the face relies more on the bones of the skull and face than the muscles. Which is why we start this series with a book on the skull. Once you master the skull you are better prepared to tackle the face and handle all of its complexity. I do my best to guide you each step of the way with schematic drawings and step by step sculpting instructions in ZBrush. I hope you enjoy!
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Landmarks Lets start by looking at some landmarks. These will be the guide posts we see as we race around doing our best sculpting the face.
- Overhang at corner of eye (supraorbital margin) - - - - - - - -
Glabella, located below the superciliary arch Nasal ridge Zygomatic on cheek Chin Angle of jaw Frontal eminence Temporal Line Step down between the frontal Eminence and the temporal line and the side of the face. - Frontal Process of the Maxilla - Lacrimal Bone - Palpebral Ligament (Eyelid)
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Skull: Proportions Lets analyze some reference and see if we can find common units of measurements. In this case we are going to look for halfs, thirds and eigths.
Mapping the Proportions of the Skull
1. Enable Spotlight using Hotkey SHIFT+Z. Select Texture\Import and load reference images into the texture palette. Select the reference image in the palette and click the ‘Add to Spotlight’ icon. Spotlight will open and the controller ‘ring’ along with the image will be visible in the viewport. Hotkey Z toggles the Spotlight Controller ON/OFF. Use Hotkey SHIFT+Z to toggle Spotlight ON/OFF. 2. Establish the halfway point of the face lengthwise and widthwise. The widthwise marker will be the ‘Eye Line’.
3. Encapsulate head in a box. Use the high point of the skull to establish the left & right sides.
4. The ‘Eye Line’ is positioned at the ½ head marker. Divide the ‘Eye Line’ into 8 equal sections. Note: In the front view, proper perspective on the depth of the top of the head in relation to the chin is lost. This may make the ‘Eye Line’ appear out of place. Often, the side view will give a better indication of the actual ‘Eye Line’. Use a reference image taken with a long focal length lens to minimize perspective distortion.
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5. Extend the first 1/8th marker in from the side of the head up along the outer margin of the orbital cavity on the zygomatic bone, up to the sphenoidal process. This marks the start of the supraorbital margin which is characterized by a distinct overhang of the orbital cavity.
6. Divide both middle 1/8th markers and establish a center space between the orbits of the eyes 1/8th wide. Note: The red line indicates the actual inner border of the orbit and the 1/8th measurement is not entirely accurate. However, it is a sufficient starting point and an easy adjustment to make later.
7. The top of the orbit is located 1/8th above the ‘Eye Line’, while the bottom of the orbit is located 1/8th below. The 1/8th used to establish the top & bottom is the same measurement as the 1/8th created when dividing the ‘Eye Line’ in Step 3.
8. The resulting rectangle shape is refined when taking into account the surrounding bones.
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9. The top of the nasal opening is located at the ½ way point of the head along the ‘Eye Line’. The bottom of the nasal opening is located 1/8th of a head below bottom of orbit of the eye and falls in line with the cheek bone (not perfect alignment, but close). The nasal opening width total is ¼ (1/8 on each side of the center line).
10. The teeth meet at ½ the distance between the bottom of the nostril opening and the chin. This is not to be confused with the level where lips part, which is higher.
11. The width of the mouth is variable depending on the individual. Typical measure places the side of the mouth in line with the center of the eye.
12. The width of the mouth can be determined by examining the plane break that occurs where the teeth go back in space.
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13. The canine teeth are a good indicator of where the plane break occurs. They mark the turning point of the mouth where it heads off to the side. This is variable from person to person.
14. Using the canine teeth as reference, the position of the lips can be extrapolated. The side of the lips are just beyond these teeth at the ½ way level of the teeth, the top/bottom of the lower lip curves equally above/below the side (1/2 marker for the teeth). The upper lip is established after the lower lip.
15. Using 1/8 increments derived from dividing the ‘Eye Line’ we have established the proportions of the skull that will assist in base mesh creation.
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Skull: Basic Shape Follow the steps below to begin. 1. Create a PolySphere on the canvas and enter Edit Mode Hotkey T. Snap the viewport to a side view by SHIFT+Click-Drag on the canvas. Toggle Perspective OFF Hotkey P and enable Floor Hotkey SHIFT+P visibility in the X-dimension. 2. CTRL+Click-Drag a rectangle mask over ¼ of lower back quadrant of the polysphere and CTRL+Click the canvas to invert the mask.
3. Use the Move Brush to push in the unmasked section of the sphere and lightly apply the Smooth Brush to refine edges.
4. CTRL+Click-Drag a rectangle mask over the lower front quadrant leaving a small, unmasked space in front of the rear lower quadrant.
5. CTRL+Click the canvas to invert the mask and enter Rotate Mode Hotkey R. SHIFT+ Click-Drag a transpose line horizontally from the front middle back, extending well past the sphere.
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6. Pull the handle that extends past the model by its center ring and rotate to establish the front plane of the face.
7. Consider the type of head being created and rotate the jaw accordingly.
Ex. Jaw that pulls back from brow.
Ex. Jaw that pulls forward from brow.
8. Once the jaw line has been established, the excess will need to be clipped. You can do this with the Trim Dynamic brush, Trim Front or the Clip Brushes.
9. A topology refinement is needed due to stretching the geometry while rotating.
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10. Press SHIFT+F to enable PolyFrame visibility. Press SHIFT+D until the geometry is at its lowest subdivision level and use the Smooth Brush to even out the topology.
11. Select Tool\Subtool\Reproject Higher Subdiv to regain the detail lost when smoothing and retain the even topology.
To the left is our improved topology. This is a great way to quickly even out topology. and can be used at any stage of your sculpting.
12. Snap the viewport to a front view by SHIFT+ClickDrag on the canvas. Use the TrimFront Brush to remove the front excess. Start the stroke above the bulge and gesture downward.
13. Snap the viewport to a side view by SHIFT+ClickDrag on the canvas. The jaw line needs revision.
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Current jaw line:
Current plane break:
14. Revise the jaw line using the Move Brush. Note: Males and Females have distinctly different jaw lines.
Females have a softer jaw line transition, especially at the angle of the mandible:
Males have a more pronounced jawline with a bulkier angle:
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15. Snap the viewport to a front view by SHIFT+ClickDrag on the canvas. The width of the head needs to be adjusted from 1 to .75 units.
16. Enter Move Mode Hotkey W and SHIFT+Click-Drag a transpose line from top middle of the head down, extending off the model.
17. Pull the handle that extends past the model by its outer ring back up to the bottom edge of the head.
18. The measure of the transpose line is recorded in units based on an internal scale. The head is 2.32 units which is a difficult number to use when laying out proportions.
19. To achieve a round number, which will be easier to work with, set Preferences\Transpose Units\ Calibration Distance to 2.
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By doubling values and using 2 vs. 1 it becomes easier to measure proportions. SHIFT+Click-Drag a transpose line from the center middle of the face out .75 units to establish the width of the head.
20. Holding SHIFT, pull the handle at the .75 marker by its outer ring horizontally toward the center until the width of the head is set. The action line stays in place acting as a measuring stick, keeping the .75.
21. With the high point of the head established, visualize what needs to be trimmed to create the wedge of the face.
22. SHIFT+D to lower the subdivision level one level. Hotkey Q to enter Draw Mode and CTRL+Click-Drag the canvas with a rectangular mask covering slightly more than the top half of the head.
23. Blur the mask by holding CTRL and clicking directly on the model. Return to Move Mode Hotkey W and pull the handle at the side of the head by its outer ring horizontally toward the center until the width of the chin is set.
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24. Now its time to Relax the mesh and remove any stretched polygons.Set the model to its highest subdivision level and then set Tool\Deformation\ Relax with a moderate value of 20 to make the topology easier to work with.
25. Apply Trim Dynamic and Smooth Brush to create clean transitions between the basic forms.
26. Snap into side view and evaluate the chin for repositioning.
27. My goal at this point is a simple form that I can build on. I am not trying to do too much but I also don’t want to do too little. Its important that all of the foundation of present and that the form, simple as it may be, also lends itself well to its future complexity.
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Skull: Facial Grid Using Transpose as a Measuring Tool A transpose line can be used as a calibration tool when setting up the facial grid to ensure proper proportion. 1. Select Tool\Deformation\Unify to modify the world scale for the model and make it easier to work with. This conforms its height to the ZBrush grid.
2. Transpose needs to be calibrated to use in horizontal measurement. Also, it must be setup to show ticks 1/8th apart to construct the facial grid properly. This will be done under Preferences\Transpose Units.
3. SHIFT+Click-Drag a transpose line horizontally from the center out past the side of the model and release the click.
4. Drag the outer ring of the handle back in so it lines up with the outside edge of the face.
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5. Set Preferences\Transpose Units\Calibration Distance to 1. Set Preferences\Transpose Units\ Minor Ticks to 4.
Mapping the Facial Grid Using PolyPaint 1. Press CTRL+D to subdivide the model until the polygon count is around 400k. 2. Prepare to PolyPaint using the Standard Brush. Turn RGB ON and Zadd OFF. Enable the Brush Icon next to the thumbnail of the head subtool in the Tool\ SubTool list.
3. Select a color to use for the guidelines (Black) and hold SHIFT while stroking to sketch a straight line across model that will be the ‘Eye Line’.
4. Toggle between Move Mode Hotkey W and Draw Mode Hotkey Q to use the ticks on the Transpose Line as a guide to layout the 1/8th markers across the ‘Eye Line’.
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5. Mark the inner boundaries for the orbit of the eyes by dividing the inner 1/8th on both sides in half.
6. Continue to use Transpose as a guide to establish the top and bottom of the orbit.
7. Mark the bottom of the nose.
8. Divide the space between the bottom of the nose and the chin in half to get the line of the teeth. Indicate the part of the lips slightly higher.
9. Mark the top ridge of the nasal opening.
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10. Refine the orbital box by indicating how the corners are ‘lopped off’ by the surrounding bony structures and sketch in the shape of the nasal cavity.
11. Expand the mark indicating the bottom of the nasal cavity out horizontally to indicate the level of the cheek bone.
12. Indicate the form outside the orbital cavity.
13. Sketch in the temporal line, frontal process, glabella and superciliary arch on the upper part of the head. Sketch in the maxilla, teeth and jaw on the lower part of the head. When the PolyPaint guides are complete turn RGB OFF.
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Skull: Sculpting the Facial Grid Overview My goal here is to establish the orbit of the eye, the muzzle of the mouth and the general shape of the maxilla bone. Follow the steps below. 1. Hold CTRL and carefully mask out the orbit of the eye using Mask Pen. CTRL+Click the canvas to invert the mask.
2. SHIFT+Click-Drag on the canvas to snap into Side View. Evaluate the depth of the orbit of the eye (use a Transpose Line if needed). It should be approximately 1/8 units deep.
3. Enter Move Mode Hotkey W and pull a horizontal Transpose Line while holding SHIFT from the outer edge of the orbit of the eye past the edge of the model.
4. Pull the inner circle on the outer handle of the Transpose Line back toward the head to create the orbital cavity.
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5. Enable Perspective Hotkey P and disable the Floor SHIFT+P. Evaluate the depth of the orbital cavity.
6. Use Move Brush to refine the shape of the orbit of the eye and begin to establish the profile of the nose and mouth. Sculpt the inward curve of the bridge of the nose. Rough in the muzzle of the maxilla, which is shaped similarly to a cylinder. Note: Not everyone has an indented bridge to their nose.
7. Use the Trim Dynamic Brush with RGB OFF to further define the profile planes of the skull.
Progress Check
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Skull: Cranial Block-in Think about the skull as two separate parts: 1. Cranial (white) 2. Mandible (red)
Specific bones of the cranial section: Frontal bone Parietal bone Parietal eminence Occipital bone Temporal bone Sphenoidal bone Zygomatic bone Maxilla and teeth Nasal bone
The brow consists of the following shapes that we want to be aware of: Glabella Supercillary Arch Overhand Supraorbital Margin
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First we will define the cheekbone by separating it from the mandible. Follow the steps below to continue. 1. Lets begin by establishing a plane change at the nasal bone using the Trim Dynamic Brush. The image at the left illustrates the plane you’ll want to make sure exists. Note: The area where the cheek connects with the nose is one of the least understood parts of the face and will be covered in-depth in a future chapter. 2. Turn Perspective OFF Hotkey P and CTRL+Click-Drag a Mask Rectangle across the entire skull roughly where the cheekbone is located.
3. The curve of the cheekbone will be created in simplified form (white) first. It will then be sculpted to a more complex form (red) later.
4. Hold CTRL+ALT and erase using Mask Pen along the contour of the simplified cheekbone.
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5. The jaw will sit inside the cheekbone. Pull the jaw in using the Move Brush. Catch some of the area above the mask to define the temporal bone.
6. In its simplest form the jaw will resemble a wedge. Ultimately it will be more of a horseshoe shape.
7. The wedge is defined at its narrowest end by the canines, which are the point of the muzzle of the jaw where the teeth turn and go back. The wedge is defined at its widest end by the angle of the jaw, also known as the ramus. The bottom edges of the mandible define the overall shape of the wedge.
8. CTRL+Click-Drag on the canvas to clear the mask and toggle Perspective ON Hotkey P. Evaluate the cheek separation using the PolyPaint guidelines.
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9. The frontal sphenoidal process of the zygomatic is the little column of bone coming up from the t-form of the cheekbone that connects to the brow. It meets the brow near the overhang on the top outside corner of the orbital cavity.
10. Toggle Perspective OFF Hotkey P. CTRL+Click-Drag a mask rectangle along the side of the head above the cheekbone, and up to the frontal sphenoidal process of the zygomatic.
11. CTRL+Click the canvas to invert the mask. Use the Move Brush and push the temporal area toward the front of the head inward.
12. Clean up the form along the jawline using Trim Dynamic and Smooth Brush. Refine the plane that runs from the ramus, along Jawline, to the canine. Use Trim Dynamic Brush & ALT to build up form, and without ALT to refine plane.
13. Evaluate progress so far.
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14. Using the Trim Dynamic Brush, cut a notch to establish a better transition of the temporal line into the overhang along the brow
15. Do not alter the brow and maintain a consistent slope all the way across the front of the face.
16. The glabella may be altered depending on the gender/character of the model at a later stage. However it’s backward slope should be maintained.
17. Continue to refine the temporal line using the Trim Dynamic Brush to shape the upper portion of the side of the head.
18. There is a visible brow to cheek step pattern which is common among most people. Some have a brow to cheek transition that is either a straight line or a more rounded form. Use the Move Brush to slightly tilt in the top outside corner of the orbital border. 30
Skull: Detours on Way to Orbit of Eye The Inner Corner of the Eye is the key to creating realistic eyes.
However, its not easy to understand. There are a lot of complex curves and the form can be misleading. To help understand it we will look at the four different quadrants of the inner corner and look at each in-depth. This makes it easier to understand and break down the form into simple and easy to reproduce structures. Before we do that, though, I want to take two detours to make sure we are familiar with the supraorbital margin, the infraorbital margin and the planes of the face.
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Detour #1: Supraorbital Margin and Infraorbital Margin While our goal here is to define the four quadrants of the orbit of the eye, I want to start that process by examining the supraorbital margin and the infraorbital margin. These are the lines that run above the eye and below the eye. Use the illustration below to locate each margin. Remember, these terms are just guides. Use the guide below to learn what each part of the word means. I often use these lines as part of my mental checklist when sculpting the eyes. I will look at the model from below and from above and make sure these lines are clean and consistent. No bumps or wavering form.
Supraorbital Margin - Supra – Above, higher level
Infraorbital Margin - Infra– Below, lower level
- Orbital – Orbit of the eye
- Orbital – Orbit of the eye
- Margin – Rim
- Margin – Rim
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Detour #2: Planes of the Orbit of the Eye Just one more detour before we get to the four quadrants of the eye. Below is an illustration of the essential structure of the orbit of the eye as well as a list of the significant plane changes. Its a great idea to keep these in mind and try to memorize them.
List of Planes to Consider - Plane break at cheek where the zygomatic goes back in space. - Inferior orbital margin forms a triangular plane as it goes toward the nose. - Front and side planes of the nose. - Front facing and side planes of the glabella. - Plane of the brow. - Inside of the eye plane.
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Skull: Four Quadrants of the Inside Corner of the eye These quadrants are essential to understanding the inside corner of the infraorbital margin. 1) Side of the nose. 2) The triangle of the inferior orbital margin that sits above the frontal process of the maxilla. 3) The lacrimal bone and how it relates to the corner of the eye and the caruncula. It is not always visible on females and is most visible in people with sunken eyes. 4) The inside portion of the glabella.
Notice how the inferior orbital margin flows right up to the glabella. It fans out to form the two triangular sections, then the rectangular sections.
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Follow the steps below to begin sculpting the orbit of the eye 1. Visualize the inferior orbital margin and its path to all the way up to the glabella.
Side View:
2. Toggle Perspective OFF Hotkey P and Shift+ClickDrag to a side view. Mask out the front of the nasal cavity to prevent it from shifting while altering the inferior orbital margin using the Move Brush. There should be a clear separation between the zygomatic and the maxilla, and space to account for the nasal bone and its side plane. 3. Using the Trim Dynamic Brush, establish the side and front planes of nasal bone. Round off the transition between the two planes.
Result:
4. Use Clay Brush to build up a triangular form to account for the frontal process of the maxilla.
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5. Leave a tiny lip on the inside of the triangle.
6. Refine frontal process of the maxilla using the Trim Dynamic Brush, adding a slight curve to top of triangle.
7. Clean up stretched topology using Tools\ Deformation\Relax with values in the 30-35 range. Fix any artifacts that appear using the Clay, Smooth, and Trim Dynamic Brushes.
After:
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8. Subdivide Hotkey CTRL+D the mesh once to increase sculpting resolution. The lacrimal groove is located beside the inferior orbital margin and contains the tear duct. The depth of the groove will also serve to further define the inferior orbital margin. Carve the neighboring groove and duct using Clay Brush with ALT.
9. Refine the lacrimal groove as it transitions into the bone using Trim Dynamic and Clay Brush.
Contour:
Planar transitions:
10. Reduce the inside corner of the glabella to a downward facing plane using the Trim Dynamic Brush.
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11. The downward facing plane of the inside corner of the glabella becomes the inside of the eye as it lines up slightly inward of the lacrimal bone.
12. Refine the area using the Clay and Trim Dynamic Brushes to adjust the glabella so it lines up slightly inward of the lacrimal bone.
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Skull: Defining the Maxilla The maxilla is probably one of the most important elements of the face when it comes to determining ethnicity and character yet you don’t find a lot of information about it in anatomy books. We start our look at the maxilla with the frontal process of the maxilla. That was my first major brush with the maxilla and it was the key to improving my sculpting of the eyes.
The zygomatic process of the maxilla connects to the barrel of the teeth pulling straight down and becoming an ‘arch’. This is a similar fashion to the glabella and its ‘capital arch’ form.
The ‘arch’ (white) tilts backwards in space. Safe zones (red) that aren’t influenced immediately by this form are the frontal process of the maxilla, infra orbital margin, the zygomatic bone itself, the barrel of the mouth and the ramus.
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Follow the steps below to begin. 1. Use the Trim Dynamic Brush to shape the curve of the ‘arch’.
Front View:
2. The Canine Teeth mark the plane change from the front to the side of the mouth. The ‘arch’ form of the frontal process of the maxilla flows downward toward this plane change.
3. Refine the ‘column’, or barrel of the mouth using the Trim Dynamic Brush. Maintain the specificity of form and plane change.
4. There is a triangular divot beside the lower corner of the nasal cavity, below the nasal labial fold and above the mouth/lips. The triangle is actually a recessed form in the skull itself. Ultimately this small depression results in a visible change in form on the surface. ¾ View:
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5. Dig in with the Clay Brush holding ALT to create the triangular depression.
6. Use the Trim Dynamic Brush to establish clean upward and downward facing planes. Smooth the transition between the two.
7. In a side view, pull the bottom corner of the nasal cavity down and back using the Move Brush.
After:
8. In a front view, pull the bottom corners of the nasal cavity out using the Move Brush.
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Skull: Defining the Upper Brow Separate elements along the supraorbital margin by isolating the glabella and the superciliary arch from the brow itself (overhang). Scientifically speaking, the skull alone can’t always be used to tell the difference between male and female. Typically, the skull and pelvis are required for gender verification. Both males and females have the same features frontal eminence, temporal line, superciliary arch. The difference is usually apparent by how soft these features are. For example, the glabella can be larger, more cro-magnon in males or smaller, more rounded in females. Follow the steps below to begin. 1. Use the Trim Dynamic Brush, stroking in a diagonally downward fashion to separate the glabella.
2. Apply the Clay Brush holding ALT to create a defined step.
3. Separate the superciliary arch from the frontal eminence by carving out a box using the Clay Brush holding ALT.
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4. Bevel the edges of the box using the Trim Dynamic Brush.
5. The temporal line is variable and can have different descending slopes depending on gender and the individual. The slope in males tends to travel more inward while females have a straighter slope.
6. Adjust the slope of the forehead using the Move Brush.
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Skull: Frontosphenoidal Process of the Zygomatic The connection between the zygomatic to the frontal bone above, and the sphenoidal bone to the side, is made by the frontosphenoidal process of the zygomatic. This form is very important to the eye and is often missed or incorrect.
Simplified side view:
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Follow the steps below to begin sculpting the frontosphenodial process. 1. The fronto sphenoidal process of the zygomatic is pulled backward and has an angle in the side view. Use Move Brush to adjust its position.
2. It is important to remember that the frontal bone at the supraorbital margin is called the ‘overhang’ because it hangs over the fronto sphenoidal process of the zygomatic. Adjust the fronto sphenoidal process of the zygomatic using the Move Brush to make sure there is a clear step up to the overhang and a step down to the cheek.
3. Add volume to the overhang, the fronto sphenoidal process of the zygomatic and the cheekbone using the Clay Buildup Brush.
4. Sculpt the added volume into planes using the Trim Dynamic Brush.
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Skull: Defining the Back of the Skull Overview The back of the skull has a few surprises for us such as the nucal line. We often skip this part of the skull because we are so enamored with the face but if we do our sculpt will suffer and could even look like it is suffering! Best to get it right. :)
Elements of the back of the skull to remember - - - - - -
Mastoid Process Occipital Bone Occipital Protuberance Parietal Bone Superior Nucle Inferior Nucle Halfway point ( Side View) is the hold for the ear and jaw.
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Follow the steps below to continue sculpting. 1. Create the mastoid process below the tail of the zygomatic bone on the base of the skull using the Clay Brush.
Side View:
2. A diagonal line coming straight out and back from the mastoid process roughly indicates the border of the occipital bone and the parietal bone. The superior nucle line comes around the back of the head from the mastoid process and is where the trapezius inserts into the skull. The inferior nucle line is located just below the superior nucle. Both lines denote a plane change (red). Use the Trim Dynamic Brush to define the superior nucle line, then the inferior nucle line.
Result of sulpt:
3. Fill in the excess space on the bottom of skull using the Clay Brush.
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4. Apply the Trim Front Brush to create a smooth plane for the base of the skull.
5. Sculpt a plane from the bottom of the mastoid process that flows into the base of the skull using the Trim Dynamic Brush.
6. Continue to refine the mastoid process using the Trim Dynamic Brush so its side plane progresses seamlessly into the back planes of the skull.
7. Refine its shape using the Move Brush.
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8. Check the angles of the back of the skull. In the illustration to the left we follow the inferior and the superior nucal line and make note of their possible angle. There is, of course, lots of variation but its always good to have a guideline.
9. Buildup a stalk where spine will attach to skull using the Clay Brush.
10. Use the Trim Front Brush to flatten the base of the stalk.
11. The major planes of the back of the skull are established by the superior and inferior nucle line (white) and the circular plane of the stalk (red), where the spine meets the skull.
12. Visualize the neck and spine attaching to the base of the skull.
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13. Now lets get the occipital protuberance. The occipital protuberance is a notch on the back of the head. It is more visible in males than females. Separate out the occipital protuberance by building up a notch using the Clay Brush and refining it using the Trim Dynamic Brush.
14. Create a minor plane change at the back of the skull using the Trim Dynamic Brush to separate the area of the occipital protuberance from the area of the mastoid process.
Skull: Corrections Its time to do some corrections. I always take a moment to correct my work and build that into my workflow. 1. With Perspective on evaluate the position of the cheek bone relative to the brow. Use the Move Brush to properly position the cheekbone (European) in a side view. Cheekbone more in-line with the brow is typical of a person of Asian descent: Cheekbone further back from the brow is typical of a person of European descent:
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2. Check the position of the brow in a ¾ view. Use the Move Brush to bring it back if it became too exaggerated while establishing the overhang of the brow.
3. Viewed from a low angle, the consistent curvedplane of the brow may have become distorted when making adjustments. Use the Move Brush to bring the overhang back in place and re-establish a consistent brow plane.
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Skull: Defining the Mandible Overview Let define the terms that we will use for the mandible. Once you’ve defined these terms it becomes easier for you and I to converse about them and it also becomes easier for you to remember them. -
Ramus (Red) is the area that ascends into the cheek.
- Angle (Blue) is the transition between the body of the mandible and the ramus. A rounder angle is typical of a female, while a sharper angle is typical of a male. - Body of mandible (White) is the part of the jaw that goes forward from the angle toward the mental protuberance (chin). - Mental Protuberance is also known as the chin. - Mandible is the term used to describe the entire jaw. - Head of the mandible is the area where the jaw connects to the cranial portion of the skull. - Coronoid process of the mandible is a thin triangular eminence projecting from the anterior portion of the upper border of the ramus.
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Follow the steps below to get started sculpting the jaw. 1. Visualize the shape of the jaw before extraction.
2. Using the Move Brush, refine the overall form of the jaw to prepare for extraction.
¾ view:
3. Holding CTRL, mask out the shape of the jaw in a side view using the Mask Pen Brush. Indicate the bottom teeth and align where they end with the cheekbone.
To aid in drawing the mask you may want to disable Render\Shadows and/or enable Render/ Flat.
4. Ensure that there is no masking on the turnaround or the bottom of the mesh as the ZBrush ‘Extract’ functionality will not operate as expected.
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5. Set Tool\SubTool\Thick value to -.3 and then select Tool\SubTool\Extract. Note: Extraction using a positive value for ‘Thick’ results in the mesh extruding outward while using a negative value results in an inward extrusion. Note: By default ZBrush creates a mask upon extraction. Clear the mask on new extractions to resume sculpting.
6. Duplicate the skull by pressing Tool\SubTool\ Duplicate or using Hotkey CTRL+SHIFT+D. Rename the original subtool ‘Skull_Orig’ to preserve it for use later in the process. Rename the copied subtool ‘Cranium’ and the extracted subtool ‘Mandible’. Save progress.
7. Select ‘Cranium’ as the active subtool and hide ‘Mandible’ and ‘Skull_Orig’. Hold CTRL and mask out the entire jaw using the Mask Pen Brush. Be sure to include the bottom of the skull.
8. CTRL+Click in viewport to invert the mask and press SHIFT+D to lower the subdivision level one time.
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9. Reduce the jaw (unmasked section) completely using either the Trim Dynamic Brush or Clip Brushes.
10. Set the ‘Mandible’ visible and evaluate the result.
Sculpting the Teeth Plate, (Alveolar) Lets get in and really sculpt the part of the maxilla that connects with the teeth, the alveolar. 1. Set the ‘Cranium’ as the active subtool and hide the ‘Mandible’. Apply the Clay Brush to build up the form for the plate that houses the upper teeth.
2. Refine the teeth plate using the Trim Dynamic Brush.
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The forms of the temporalis and zygomatic overlap and connect with the barrel shape of the teeth:
Refining the Jaw Lets refine the mandible now and get all its essential form intact. 1. Select the ‘Mandible’ and enter Solo Mode Hotkey -. With Symmetry Enabled Hotkey X, smooth the edges of the extracted mesh. Use the Move Elastic Brush to bring the Coronoid Process inward.
2. Enable Brush\Auto Masking\BackfaceMasking and sculpt the head of the mandible using the Clay Brush.
3. The head of the mandible is shaped like a cylinder. It connects to the neck of the mandible and then flows down to the angle of the jaw.
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4. The bottom teeth reside on a plate in a similar fashion to the upper teeth. The plane of this plate travels backward to the inside of the ramus.
5. Use the Clay Buildup Brush to add form to the inside of the coronoid process. Also, add form around the jaw by the teeth, thickening the area.
6. Smooth the form and add refine the planes of the jaw using the Trim Dynamic Brush in a top view. Define the alveolar section (bottom teeth plate) which has a horseshoe shape that transitions inside the coronoid process as it travel back. Define the oblique line which indicates the plane change where the transition to the alveolar section takes place.
7. Continue to define the oblique line as it flows toward the front of the jaw and the mental protuberance. Build up the mental protuberance using the Clay Brush and shape it with the Trim Dynamic Brush (make sure to enable Brush\Auto Masking\BackFaceMasking for these brushes when working with them on this area).
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8. Adjust the alveolar section so it clearly travels behind the coronoid process.
9. Add more form inside the alveolar section of the jaw to accommodate the teeth.
Reference Check Time to check the sculpt against the reference. to do this I use Spotlight. 1. Enable Spotlight using Hotkey SHIFT+Z. Select the side view of the skull as a reference image and position it in the viewport at roughly the same scale and position as the model. Use the Spotlight Controller to lower the reference image opacity by clicking the ‘Opacity Icon’ and dragging it counter clockwise around the ring.
2. Use the reference image to make adjustments to the model. Be as faithful to reference as necessary, taking into account potential unknowns like gender and ethnicity.
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3. Make sure there is enough space for the teeth. Rely on the initial 1/8 measurement scale established when mapping out the facial grid. At this stage we are setting up to add the teeth as separate SubTools. It might look weird now butjust keep going or read ahead if you want to see where we end up One note, in these images perspective is turned off so it looks a bit different.
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Sculpting the Teeth Overview Humans have the same number of teeth on the top and bottom of their mouths. Each row consists of: - 4 Incisors (front teeth) - 2 Canines (located next to the incisors, the transition point where the plane of the mouth goes back in space) - 4 Premolars (located in between the canines and molars) - 6 Molars (located next to the premolars at the back of the mouth) For sculpting purposes it is only necessary to create half of the top row of teeth and then mirror them to the opposite side. This complete top row can then be mirrored again to form a complete set of bottom teeth. Once all of the teeth are in place, top and bottom, they can be refined individually.
Mapping the Teeth Using PolyPaint 1. Select ‘Skull_Orig’ as the active subtool and hide all other parts of the model. The original jaw shape will be used to extract a rectangular ringed guide piece that will be helpful in creating the teeth. Set Tool\SubTool\Thick value to -.3 and then select Tool\SubTool\Extract. Name the new subtool ‘teethGuide’.
Results:
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2. With the ‘teethGuide’ as the active subtool, select white as the foreground color in the Color menu. Select Color\Fill Object to fill ‘teethGuide’ with white, removing the original PolyPaint guidelines. Enable PolyPaint visibility on the ‘Mandible’ and ‘Cranium’ subtools and start painting straight lines to separate teeth as shown in the illustration to the left. Note, the lower teeth are slightly smaller. 3. Map out the canines using the edge of the nasal cavity as a reference point. The edge of the nasal cavity falls in line with the center of the canines. Allocate tooth width appropriately, taking into account the 2 incisors that will be created next.
4. Divide the front space in half for the incisors.
5. 5 teeth will fit into the remaining space. Take into account that the premolars are smaller than the molars. Map the two premolars first, next to the canines.
6. Divide the remaining space into thirds for the 3 molars.
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7. The layout for the bottom row of teeth is similar to the top except that the teeth vary in size a bit from their upper counterparts. Indicate the bottom teeth by staggering the distribution a bit to differentiate it from the top.
Creating Teeth ShadowBox will be used to create an incisor-like and a molar-like template from which to sculpt all of the teeth. Open Lightbox Hotkey , and load the Tool \Shadowbox 28.ZTL file. Draw the shadowbox in the viewport and enter Edit Mode Hotkey T. Disable Perspective Hotkey P and snap the viewport to the ‘Back’ view of the shadowbox template.
Incisor Template
1. Create the incisor template first. Set the Mask Stroke to Rectangle and CTRL+Drag a basic rectangle mask.
2. Snap the viewport to the ‘Right’ view of the shadowbox template and mask another rectangle. Toggle Tools\SubTool\ShadowBox to see the resulting geometry.
3. The incisor is more knife-like at its front. Use the Trim Dynamic Brush to carve the’ blade’ in on the back side of the template.
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4. Create a slight curve to the front of the template using the Trim Dynamic Brush.
5. Teeth pull in slightly in their middle as they connect with their roots. Use the Move Brush in a front view to bring the tooth in slightly.
Side view:
Molar Template 1. Create the molar template second using the same techniques used to make the incisor version. Sculpt the molar to resemble the image to the left.
Positioning Teeth 1. Return to the working file containing the skull and jaw and enable Transparency. Tools\SubTool\ Append both templates to the working file. Resize them one at a time using Deformation\Size with a value of -100 (twice) to bring them to approximately the correct size in relation to the skull.
2. With the tooth guide visible, Enter Move Mode Hotkey W and use a transpose line to position the molar template. Select the middle handle, inner circle, of the transpose line to drag the template into place.
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3. Enter Rotate Mode Hotkey R and rotate the molar to match the gum line.
4. Position the incisor template in a similar fashion to the method used for positioning the molar.
5. Using Subtool\Duplicate, make enough copies to fill in one side of the upper row of teeth. Move and rotate each tooth into position. Make sure to duplicate and position the appropriate template. Teeth with guide hidden:
Refining Individual Teeth 1. In the Tools\Subtool list, select the top tooth in the list and make sure the rest of the teeth (and only teeth) are below it. Reorder, if necessary, so a consecutive list of teeth is at the bottom of the list. Select Tools\SubTool\Merge Down to consolidate all of the teeth into one subtool.
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2. Select Tools\Polygroups\Auto Groups.
3. Set Brush\Auto Masking\Mask By Polygroups to 100 to allow transposing individual teeth without affecting any others. Individually adjust teeth, refining spacing, etc. using Move mode. 4. Conitnue, making any necessary adjustments and complete one half-set.
Mirroring Teeth 1. Mirror this half-set over to the other side using ZPlugin\SubTool Master. 2. Select Mirror in the SubTool Master operation list. 3. Set the Mirror options to ’Merge into one SubTool’ and ‘X Axis’ (left to right) and select OK. Result:
4. Using SubTool Master, mirror the teeth again. This time set the Mirror options to ‘Append as new SubTool’ and ‘Y axis’ (top to bottom) and select OK.
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5. The bottom teeth need to be positioned properly. Reset Brush\Auto Masking\Mask By Polygroups to 0 so the entire bottom row of teeth can be moved together. Enter Move Mode Hotkey W and transpose the back molar so it aligns with the back bottom gum line.
6. Enter Rotate Mode Hotkey R and use the back molar as a pivot for the transpose line. Rotate the bottom row of teeth until the front incisors are aligned with the front of the bottom gum line.
7. Make sure that Symmetry Hotkey X is enabled and enter Scale Mode Hotkey E. Slightly reduce the set proportionally. Now enter Move Mode Hotkey W and slightly non-proportionately scale and refine the final position.
8. Use the Inflate Brush to bring the teeth closer together and add a more natural appearance.
9. With Symmetry OFF Hotkey X, selectively use the H-Polish Brush in spots to add more naturalism.
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Mandible Refinement to Accommodate the Teeth 1. The alveolar section of the mandible may need more bulk in the rear to cover the roots of the teeth.
2. Enable Brush\Auto Masking\BackfaceMasking and add form using the Clay Brush.
3. Adjust the gums to give the impression that they are conforming to the teeth as they are inserting into the bone. Buildup small channels using the Clay Brush. The gum-line by the molars form a small ledge.
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Final Progress Check Cleanup the skull using Trim Dynamic, Clay, Smooth and hPolish Brushes. Apply them in a fluid manner without perfecting form and use reference to make sure the basic elements are solid. Since we are dealing with bone remember to keep your strokes on the hard side of things. Emphasis edges when you can and accentuate corners. Try overdoing it a few times just to see how far you can take it.
Well, I hope you enjoyed this companion to our Anatomy of the Face workshop at ZBrushWorkshops. I hope you learned something and you feel ready to get in and tackle the face with a whole new set of tools. Thank you so much for reading this and good luck with all your sculpting endeavours. Ryan Kingslien
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