3D Breast Modelling


The ultimate goal of 3D garment design is to be able to virtually drape and design garments on a 3D avatar with the computer simultaneously creating a 2D pattern.  As futuristic as it sounds, software to accomplish this already exists.  As is currently the case with all mass customization technologies however, there have been issues with achieving an accurate fit on “non-standard” bodies.  Translating 3D shapes to 2D patterns is not a simple process, even for computers.  



The malleability of breast tissue further complicates 3D computer modelling because breast measurements are not static.  Breast measurements change as volume is manipulated with movement or with the structure of a bra.  While it is quite easy to model a firm breast, most natural breasts have some degree of sag making them difficult to measure.  Also, the inframammary fold, which references the perimeter of the breast mound, is often difficult to identify and is easily moved.  

  There is no static position for breasts so 3D modelling must take into account how different bras create different silhouettes and bust girths.  Modelling a natural breast is almost a moot point since most women will wear some sort of supporting structure.  Modelling of breast mounds must therefore  consider how the desired support for the breast in the given context.  For example, modelling for nightwear, sportswear, evening wear and daywear would look very different as the breasts are supported differently during these activities.  Bras are designed to provide lift and support by manipulating breast tissue, so a model of any given breast could change with a bra offering different support.  

The power of a bra to change breast parameters is an often misunderstood fact that must be understood for proper 3D modelling of the breast.

Since 3D breast modelling requires accurate measurement parameters, it is imperative that individual preferences be considered as well as actual mound size.  Individuals may prefer more or less garment ease in different bra styles so bra size is also not static.  An individual may prefer a sister sized bra to their recommended size and this can drastically alter breast parameters.  Although the “actual cup size” of a figure remains constant (excluding a physical size change) the “visual cup size” of breast mounds change with mound manipulation in various bras.  The Bra and Garment Synergy page discusses how this is possible.  To effectively model breast mounds much more than just size must be considered.  It needs to be understood how a 34D bra can support breasts so as to create a 34B visual cup size.

It is imperative to understand how the “actual cup size” of a breast mound can be manipulated to a have a different “visual cup size.” 

The lingerie industry uses a hemispheric breast model to base sizing on but natural breasts are seldom hemispherical even contained in a bra.  Understanding the relationship between the hemispheric breast model, non-hemispheric breast containment, and the effects on bust girth is absolutely essential to 3D breast modelling.  For example, it has long been thought that a change in cup size on a the same band, going from a 36C to a 36D for example, would change bust girth by 2 to 2.5cm (.89 – 1 inch).

A quick test on fit models with an array of cup sizes, in any style of bra, quickly discounts the myth of bust girth changing by 2 to 2.5cm (.89 – 1 inch) between cup size on the same band.

My upcoming text “Breast, Bra, Garment: The Mathematical Models Behind Sizing and Fit” discusses the intricacies of breast mound manipulation and offers methodologies to translate 3D manipulation to a 2D pattern.  These methodologies combined with body weight and height distribution will improve the fit of 3D computer bra design.  Join our mailing list on the upper right if you would like to be notified when this book is released.




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