Most poor results in 3D scanning come not from insufficient accuracy, but from hair, makeup, lighting and posture not being standardized before capture. Whether to use markers is only one part of the problem.
1. What markers are for
Markers are mainly used for multi-view stitching, dynamic tracking or scenarios that need a stable reference. For a static facial scan completed in one shot, markers are usually not needed on the face; whether to use them should follow the operating instructions and capture mode of the specific model.
If markers are genuinely required, their position, count and application method should follow the procedure, and the two captures should be consistent. Adding or removing markers at will makes the data incomparable.
2. Hair: the area where data is most often lost
The hairline, sideburns, preauricular area and mandibular border are common areas of missing data. Bangs covering the forehead, loose hair over the preauricular area and heavy hair accessories that change the head contour all affect later measurement and comparison.
Use a headband or hair cap that does not change the head shape to gather the hair as much as possible; do not use temporary fillers to change the hairline. After capture, check mesh completeness in the software, and rescan any gaps before moving on to analysis.
3. Makeup, oil and reflections
Foundation changes skin tone and texture, and highlighter, glitter and oily shine cause local reflections that affect the stability of optical capture. When skin texture or skin tone analysis is needed, a bare face or cleansing according to the institution's standard requirements is recommended.
If a completely bare face is not possible, at least keep the makeup conditions consistent between the two captures of the same patient. Otherwise, differences in the color map may come from makeup rather than the skin condition itself.
4. Dark skin and oily skin
Optical capture depends on surface reflection. With dark skin, oily skin or perspiration, areas may appear too dark, overexposed or with unclear texture. These issues are usually solved by adjusting exposure, adding fill light or cleaning again; they do not mean the face “cannot be scanned”.
To judge whether a capture is acceptable, do not rely only on whether the model looks good on screen; check whether the mesh is continuous, the texture is complete and the key landmarks are clear. The same capture settings and acceptance criteria should apply to all skin tones.
5. Expression, posture and mouth opening
Structural measurement usually requires a neutral expression, relaxed occlusion and a level gaze. Frowning, smiling, tilting the head down or turning it all change soft-tissue form. When dynamic expressions need to be assessed, use a 4D mode that supports continuous capture rather than substituting a single static image.
| Interfering factor | Common symptom | How to handle it | Effect on comparison |
|---|---|---|---|
| Hair obstruction | Missing hairline, preauricular area and mandibular border | Gather with a headband, rescan the gaps | Contour and area metrics distorted |
| Makeup and oily shine | Local reflections, texture obscured | Bare face or standardized makeup, cleanse and control oil | Skin tone and texture differences misread |
| Dark or oily skin | Areas too dark or overexposed | Adjust exposure and fill light, check the mesh | Lower data completeness |
| Expression and posture | Soft-tissue deformation, left-right asymmetry | Neutral expression, level gaze | Inconsistent definitions between captures |
| Objects in the way | Marks from glasses, masks and accessories | Remove them before capture; wait for marks to fade if necessary | Local morphology altered |
6. Four post-capture checks
- Is the mesh continuous, and are there holes in key areas?
- Is the texture complete, without obvious reflections or shadows?
- Is the pose centered, without obvious head rotation?
- Are this capture's conditions recorded so they can be reproduced next time?
Related pages: MVS-P6, MVS-C6, MVS-M6, MVS-800, ZETTA, 3D digital plastic surgery system.
This article describes product functions and processes and does not constitute medical advice; specific configurations, metrics and deliverables are subject to the product version and the contract.