KMK-Dacii: Designing Software to Support Body-Fit Products
Digital Human Research Center (Former NIBH: National Institute of Bioscience and Human-Technoloy) developed a software that supports body-fit product designing (i.e., shoes, clothes, eyeglass frames and prosthetic appliances). The software is available to the public for a fee from the Japan Industrial Technology Association.
This software is a program for the body shape analysis by Free Form Deformation (FFD) method (Figure 1). It works with the Windows NT/2000 environment. This software makes it possible to design products which fit individual body shapes.
Figure 1 : Example of a Display from the Software
The first licensee, I-Ware Laboratory Co., Ltd., has started to offer information services using this software with their proprietary information terminal INFOOT, a 3-D foot scanner. At shoe stores, a customer's foot shapes will be measured, and then the shapes will be compared against the mean shape. By utilizing the FFD transformation feature of this software, the company intends to provide shoes that fit an individual consumer's foot shape with a reasonable price and in a prompt manner.
One-dimensional quantities, such as human body dimensions, have been mainly used for designing products that fit a human body.
However, these one-dimensional quantities could not fully reflect "the 3-D shape features", such as roundness and bending of a body. In order to design better fitting products, methods that would enable the processing of 3-D shape information were needed.
DHRC developed a technology that can be applied to product design and the technology of statistical processing of 3-D shapes, by formulating the individual differences of 3-D body shapes.
In this technology, the differences between two 3-D human body shapes are formulated using the FFD (Free Form Deformation) technique, a CG based technique. This technology has been utilized to develop new dressmaking dummies in a collaboration study with Bunka Fashion College. We also have collaboration studies with domestic and international manufacturers of shoes, eyeglass frames, gas masks and prosthetic appliances.
This time, we are providing a PC-based software package so that it will be easier to utilize this technology.
The FFD technique smoothly transforms a shape of an object by setting control lattice points around the object and then moving these control lattice points (Figure 2).
Figure 2 : FFD technique
DHRC considered using distortion of the lattice points rather than distorting the object.
Provided that there are two objects, and all of their data points anatomically correspond to each other, it is possible to derive the FFD transform lattice (equivalent to spatial distortion) that will transform human body shape A into human body shape B. Consequently, the FFD transform lattice will be the formulation of the "individual differences" of two human body shapes, A and B. For example, when human body shape A has a standard, or ideal, body shape and a ready-made product, A', fits well, it is possible obtain the new product shape B' that fits human shape B, by applying the FFD transform lattice, which shows the individual differences of A and B, to product shape A' (Figure 3).
Figure 3 : Formulation and Application of Individual Differences Based on FFD Technique
In addition, the magnitude of the distortion of the A to B FFD transform lattice represents the differences in the 3-D shape of two human body shapes (morphological distance between the shapes). By analyzing the distance matrix between shapes using multidimensional scaling method, a distribution map, such as Figure 4, can be obtained. Also, a virtual shape on this distribution map, such as mean shapes and the standard deviation shapes, can be calculated. Human Body Statistica, a new software for these purposes, is also available.
This software is a basic tool to achieve such "product transformation based on the individual differences of the 3-D body shape". It has features to import 2 body shapes, calculate the FFD transform lattice that transforms the original shape into a target shape, and to transform a product shape based on the resulting transform lattice. Moreover, by superimposing two shapes, the differences between the two shapes can be observed readily.
Figure 4 : Foot Shape Distribution of Japanese Females by FFD Technique