# ZBrush — Likeness and Age Research Research for the two ZBrush topics that were still open in [[ZBrush — Tutorials]]: 1. sculpting a **likeness from 19th-century photographs** without a scan; 2. **age progression and regression**, to sculpt the *dated self*. It closes those research items and sets the rules the character artist and historian work to. Tutorials that apply it: [[Tutorial — Starting a Head and Base Body in ZBrush]] and [[Tutorial — Flat Albedo from Polypaint]]. ## 1. Reading early photographs as evidence ### 1.1 Mirror reversal - **Most daguerreotypes (and tintypes) are laterally reversed.** Early cameras had no reversing prism or mirror, so the plate is a mirror image of the sitter. - **How to tell:** - lettering reads backwards; - buttons are on the wrong side for the period's men's or women's clothing; - a hair part or a known mark is on the opposite side from other images. - **Copies can flip it back.** A copy daguerreotype, a later paper print or a modern reproduction may have been re-reversed. **Every image in the likeness log needs a stated orientation** (reversed / corrected / unknown) and the reason. - **Asymmetry is the trap.** Reversal makes a face look different, which is why 19th-century viewers read character into reversed portraits. Build asymmetries only from images whose orientation you are sure of. ### 1.2 Colour sensitivity (daguerreotype and wet-plate collodion) Early plates were sensitive almost only to **blue, violet and ultraviolet** light. As a result: | Real colour | How it records | Consequence for us | |---|---|---| | Warm, ruddy or tanned skin | Darker than it was | **Don't read skin tone from the grey value.** Use written descriptions and painted portraits | | Fair skin | Very light | Can look paler than it was | | Blue eyes | Very pale, sometimes almost white | Eye colour must come from written records, not the plate | | Blond or red hair | Dark or black | Hair colour from written records | | Freckles (yellowish) | Much more visible than in life | Don't over-paint freckles from photographs | | Lips, rosy cheeks | Dark or lost in shadow | Lip colour is an interpretation; note it on the label | **Hand-colouring was common:** cheeks tinted pink, and gold on jewellery. Treat colour on a daguerreotype as the studio's addition, not evidence. ### 1.3 Exposure and pose - **Exposures took seconds to minutes.** Sitters used head rests and held a fixed, set expression. The **stern look is the process, not the person**. Our neutral should be relaxed ([[ZBrush — Sculpting for MetaHuman]]). - **Studio lighting** came from a skylight or window, often from above and to one side. Shadows under the brow and nose are lighting, not anatomy. Don't sculpt the shadow. ### 1.4 Lens and perspective - **Portrait lenses and short studio distances change proportions.** A close camera enlarges the nose and shrinks the ears. - **In ZBrush:** - match the view with **Perspective** on; - adjust the **focal length / angle of view** until the reference and the model line up on a known distance (for example the width between the eye corners against the width of the mouth); - then **StoreCamera** for that image. - **Keep one stored camera per reference image.** Judge likeness only in that image's camera, and judge proportions in an orthographic side view. ## 2. What is evidence and what is interpretation Forensic facial reconstruction offers a useful model. **Overall face shape and proportions** can be reconstructed reliably. **Lip thickness, mouth width, nose length, skin tone, eye and hair colour** are uncertain without direct evidence. Our figures have photographs, so we know more than a skull-based reconstruction would. The same honesty rule still applies: | Feature | Evidence we rely on | Label wording if not documented | |---|---|---| | Face shape, proportions, nose, brow, jaw | Photographs checked for orientation, several angles if they exist | — | | Asymmetries, marks | Only from orientation-verified images | "Based on photographs" | | Skin tone | Written descriptions, painted portraits, historian's judgement | "Skin tone is an interpretation" | | Eye and hair colour | Written descriptions (letters, passports, biographies) | "Eye/hair colour from written description" or "interpreted" | | Expressions beyond neutral | Written descriptions only | See [[Tutorial — Sculpting Expression Targets for the Expression Editor]] | **Record every one of these decisions in the likeness log.** The historian signs off on the log, not only on the final model. ## 3. Age: sculpting the dated self ### 3.1 What changes with age Facial ageing works from the **inside out**: 1. **Bone.** The eye sockets widen, the midface (maxilla) recedes, the pyriform aperture around the nose widens, and the jaw loses height and definition. 2. **Deep fat.** It loses volume and sags, which hollows the midface, deepens the tear trough and flattens the cheekbones. 3. **Superficial fat.** It moves downward. The upper and middle compartments thin and the lower ones thicken, giving **jowls, deeper nasolabial folds and perioral folds**. Compartments with looser connective tissue (nasolabial, infraorbital) sag first. 4. **Skin.** It loses elasticity and gains fine wrinkles, uneven pigment and texture. **This goes in the maps**, not the mesh ([[Tutorial — Baking Detail Maps for MetaHuman]]). **Order of work in ZBrush:** make each age change on its own layer (`age_bone`, `age_deepfat`, `age_superficial`) in the order above. Keep skin texture for the detail pass. This keeps age adjustable and makes it clear what was changed. ### 3.2 Regression (younger than the photographs) This is the common case for us. **Example:** the 1847 comet night needs **Maria Mitchell at 29**, but the Maria Mitchell Association's portraits of her date from **about 1851 to 1888**. The earliest is about four years later, and most are much later. 1. Start from the **earliest reliable image**. For a small gap (under 5 years), change very little: slightly fuller midface fat and less nasolabial depth. 2. For a larger gap, work the layers backwards: restore deep fat volume first, then lift the superficial fat, then sharpen the jawline. **Don't change the bone** unless the gap covers middle age. 3. **Keep the landmarks** (eye shape, nose, ear form) from the photographs. These change least with age and carry the likeness. 4. **Label it:** "Appearance at 29 is reconstructed from portraits taken at 33 and later." ### 3.3 Progression (older than the photographs) This is rarer. Work the layers forwards. The skin texture change is the most visible part at kiosk distance. - **Oldify** (3D Scan Store) supplies scan-based wrinkle layers and skin textures (personal licence about £60; **commercial licence about £260**). It wraps to its own base head, so **it can't be applied directly to MetaHuman topology.** Use it as reference, or project it onto a free-topology sculpt *before* Mesh to MetaHuman. ## 4. Getting the reference - **The Maria Mitchell Association's historic photo collection** holds daguerreotypes, tintypes and albumen prints from about 1840 to 1910, including several portraits of Mitchell (about 1851–1888). - **To request images:** send the Publication and Use Agreement to the curator. - **Rights warning:** reproduction permission is **one-time, non-transferable and for a single format**. A 3D likeness shown on a kiosk, headset and phone is several formats. **Negotiate a use licence that covers building and showing a digital likeness on all surfaces** before sculpting from MMA images, or work only from public-domain copies (for example the Library of Congress copy negative). Add this to the rights map. - **Other sources:** the Library of Congress, the Massachusetts Historical Society's early-photograph collections, Vassar College (Mitchell's later years) and the Nantucket Historical Association. ## 5. Training (external) | Title | Provider | Type | Link | Use | |---|---|---|---|---| | Recreating a Historical Portrait in 3D | The Gnomon Workshop | Paid course | https://www.thegnomonworkshop.com/workshops/recreating-a-historical-portrait-in-3d | Closest match to our task; check content before buying | | Creating Hyper Realistic Characters in ZBrush | The Gnomon Workshop | Paid course | https://thegnomonworkshop.com/workshops/creating-hyper-realistic-characters-in-zbrush | Realistic head anatomy and detail | | Zbrush Character Likeness Sculpting Tutorial | Udemy | Paid course | https://www.udemy.com/course/zbrush-2021-character-likeness-sculpting-tutorial/ | Likeness from photographs (older ZBrush version; the method still applies) | | Aging Characters in ZBrush | Pluralsight | Paid course | https://www.pluralsight.com/courses/aging-characters-zbrush-143 | Age progression | | Creating an Aged Portrait in ZBrush | Pluralsight | Paid course | https://www.pluralsight.com/courses/an-aged-portrait-zbrush-1134 | Age progression | | Oldify: character ageing kit | 3D Scan Store | Tool / reference | https://www.3dscanstore.com/tools/oldify | Wrinkle and skin reference (licence note above) | ## 6. Decisions - **Likeness log fields per image:** source, date, format, orientation (reversed / corrected / unknown), lens notes, stored ZBrush camera name, rights status. - **Colour comes from words, not plates.** Skin, eye and hair colour come from written or painted evidence and are labelled when interpreted. - **Age is layered** (bone → deep fat → superficial fat → skin maps) so the historian can review each step. - **Rights before sculpting.** Clear MMA image use for a multi-surface digital likeness before production. ## Sources - The Huntington, "Reflecting on Daguerreotypes" (lateral reversal; exposure): https://www.huntington.org/verso/reflecting-daguerreotypes - Society of American Archivists, "lateral reversal": https://dictionary.archivists.org/entry/lateral-reversal.html - E. A. Topping, "When Yellow Is Black and Blue Is White," *Military Images*, 3 December 2020: https://www.militaryimagesmagazine-digital.com/2020/12/03/color-wet-plate-photography-winter-2021/ - Novedge, ZBrush StoreCamera workflow (focal length and angle of view): https://novedge.com/blogs/design-news/zbrush-tip-storecamera-workflow-for-repeatable-zbrush-camera-views - Live Science, "Facial reconstructions help the past come alive. But are they accurate?" (5 November 2023): https://www.livescience.com/archaeology/facial-reconstructions-help-the-past-come-alive-but-are-they-accurate - K. I. Nam, S. Shin, J. Song, "Anatomical importance of fat compartments in facial aging: a review," *Anatomical and Biological Anthropology* (2025): https://www.researchgate.net/publication/396085291_Anatomical_importance_of_fat_compartments_in_facial_aging_a_review - S. R. Coleman and R. Grover, "The anatomy of the aging face: volume loss and changes in 3-dimensional topography," *Aesthetic Surgery Journal* 26 (2006): https://www.sciencedirect.com/science/article/abs/pii/S1090820X05004590 - "Facial bone aging: an update and literature review" (2026, PubMed 41716329): https://pubmed.ncbi.nlm.nih.gov/41716329/ - Maria Mitchell Association, Historic Photo Collection: https://www.mariamitchell.org/historic-photo-collection - Library of Congress, Maria Mitchell copy negative: https://www.loc.gov/resource/cph.3b39128/ - Massachusetts Historical Society, Early Photographs: https://www.masshist.org/features/early-photographs - CG Channel, Oldify ages ZBrush sculpts (licence prices): https://www.cgchannel.com/2022/04/oldify-instantly-ages-your-zbrush-character-sculpts/ - Full list: [[Sources — 2026-09-19]]