Page 155 - Anthropometry, Apparel Sizing and Design

150 Anthropometry, Apparel Sizing and Design

This lack of understanding of the scanning technology ultimately led to misunder-
standings of the nature of scan measurements, which at times impeded effective devel-
opment of methods of creating and using scan data.
There are two factors in the discussion of the “accuracy” of the scanner measure-
ments that were not often discussed or resolved. One is the fact that the human body is
an organic form that is in a state of constant change, so no method of measurement will
result in identical measurements, even when taken within the same time frame. Mea-
surements taken over time will vary even more. Changes in the posture of the person
being measured, or in the placement of landmarks, combined with physiological
changes (water loss or gain in the body driven by hormonal changes, compression
of the spine that occurs throughout the day) result in measurement variation not related
to the sophistication of the measuring tool. The other is the fact that the body is mal-
leable and compressible, whereas the scan is a digital “statue” of the body. An argu-
ment can be made that the digital body created with a properly calibrated scanner is a
more reliable object than the body itself; it is the body captured in a certain time and
posture, and every measurement taken from the scan (as long as landmarks are iden-
tical) will be constant and will relate to one another in a valid manner. If this philos-
ophy is adopted, then scan measurements from a calibrated scanner are the “accurate”
value and can form the basis for clothing design and sizing systems in the nondigital
real world if chosen and used in a valid manner.

6.2.2 Use of 3-D body scans and data from scans
in apparel studies

Early use of scan data focused only on extracted linear measurements from the scans.
Full-body 3-D scanning provided data for anthropometric studies of various
populations, body shape analysis based on simple circumferences, extraction of mea-
surements as the basis for custom-made clothing, automatic size selection, and the
creation of avatars for size selection (Robinette et al., 1999; Bougourd and
Treleaven, 2014; Devarajan and Istook, 2004; Hye, 1999; Corcoran, 2004; Lerch
et al., 2007).
However, there were also early attempts to use the scans in ways that used more of
the complex 3-D data from the scan. Robinette and Whitestone (1992) conducted an
early study comparing 3-D head scans of army personnel with 3-D scans of helmets
and proposed similar studies to align and merge clothed and unclothed body scans to
directly compare clothing-to-body relationships in 3-D (Robinette and Whitestone,
1992). Circumferential slices of such scans provided precise data on the distance
of the worn clothing from the body (see Fig. 6.5). Many studies of this nature have
been conducted of firefighter gear for which the gap between clothing and body that
captures still air can be thermally protective and for cooling vests that rely on contact
of the vest with the body surface for conductive cooling (Park and Langseth-Schmidt,
2016; Deng et al., 2018; Branson et al., 2005).
Three-dimensional body scans are also used in the manufacture of dress forms that
precisely duplicate the size, shape, proportions, and posture of an apparel firm’s fit
model. Most dress forms in the past (except those made for lingerie or swimwear) have