**2.1. CASP methodology**

We tried to establish and improve the classification, but we developed a completely novel approach instead. Curvature graphs were not the main observation object any more. Rather, we observe the spatial surface, where distances from the created plane to the surface are valuated and collected in four values, which are characteristic for the observed surface. It is named CASP methodology [8]. The four properties that characterize surfaces are as follows:


Furthermore, combinations of quotients of those values have proven several charts and properties of observed parts of surfaces. CASP methodology is a widely applicable approach in fields of use where a 3D virtual model is present. CASP methodology was performed also on garments for people with postural disorders and spinal deformities.

First, we have to explain the meaning of the four properties.

**Curvature** goes from − to + sign. Zero determines a neutral curvature and represents a plane. Negative values determine a concave surface and positive values are for convex surfaces, as **Figure 1** shows. Values are calculated as the arithmetic average of normalized *n* × *n* distances, including a preposition sign. They are arranged in the *n* × *n* matrix. The *n* × *n* matrix follows natural directions, and is not the same as in mathematical writing. Mathematically, it has swapped rows over the middle row. The *n* × *n* matrix starts with entry (0,0) at the left bottom corner [8–11].

The starting point on the analyzed surface is also marked at the bottom left side. This enables us to locate the position of the same point in the 3D space and in the *n* × *n* matrix.

CASP Methodology for Virtual Prototyping of Garments for People with Postural Disorders and Spinal Deformities http://dx.doi.org/10.5772/intechopen.68632 73

**Figure 1.** Curvature.

• Lead-in

• Crown

• Hard/crude • Acceleration

several terms [6].

are as follows:

corner [8–11].

• Curvature—C,

• Acceleration—A, • Symmetry—S, and • Proportionality—P.

**2.1. CASP methodology**

Not all researchers use all terms in their works, and they agree that the list is not complete or perfect. Some of the terms are similar, while some characteristics can be described with

We tried to establish and improve the classification, but we developed a completely novel approach instead. Curvature graphs were not the main observation object any more. Rather, we observe the spatial surface, where distances from the created plane to the surface are valuated and collected in four values, which are characteristic for the observed surface. It is named CASP methodology [8]. The four properties that characterize surfaces

Furthermore, combinations of quotients of those values have proven several charts and properties of observed parts of surfaces. CASP methodology is a widely applicable approach in fields of use where a 3D virtual model is present. CASP methodology was performed also on

**Curvature** goes from − to + sign. Zero determines a neutral curvature and represents a plane. Negative values determine a concave surface and positive values are for convex surfaces, as **Figure 1** shows. Values are calculated as the arithmetic average of normalized *n* × *n* distances, including a preposition sign. They are arranged in the *n* × *n* matrix. The *n* × *n* matrix follows natural directions, and is not the same as in mathematical writing. Mathematically, it has swapped rows over the middle row. The *n* × *n* matrix starts with entry (0,0) at the left bottom

The starting point on the analyzed surface is also marked at the bottom left side. This enables

us to locate the position of the same point in the 3D space and in the *n* × *n* matrix.

garments for people with postural disorders and spinal deformities.

First, we have to explain the meaning of the four properties.

• Soft/sharp • S-shaped

72 Innovations in Spinal Deformities and Postural Disorders

**Acceleration** is a property observed in a longitudinal direction and has higher values on curves where the curvature changes more. A typical accelerated surface is shown in **Figure 2**.

**Symmetry** compares the left and right sides of a surface. It takes just positive values. Zero means perfect symmetry of a surface. Values for *S* are observed over the middle column of the *n* × *n* matrix, as in **Figure 3**. Symmetry can be detected as the arithmetical average of differences between entities' pairs compared over the middle column in the *n* × *n* matrix.

**Proportionality** is the fourth property to indicate the size or width of the surface. It is calculated as a ratio between the length and width of the observed surface, as shown in **Figure 4**. As described in Ref. [12], it has to be projected on a triangular *n* × *n* plane.

The whole *n* × *n* procedure is based on the use of the graphical algorithm Grasshopper® (GH) [11], which is add-in integrated with the 3D modeling tool Rhinoceros (RH) [12]. Parametrical procedures are created by dragging components onto a canvas. Outputs of these components are then connected to the inputs of subsequent components, and so on. Grasshopper is used mainly to build generative algorithms and it acts like a programming tool. Many of Grasshopper's components create 3D geometry. Procedures may also process other types of algorithms, including numeric, textual, audiovisual or haptic applications. We used GH because of complex algorithms that can be connected and combined easily. Our procedure for analyzing digitized surface geometries exists in 10 steps [8–11].

**Figure 2.** Accelerated surface.

**Figure 3.** Symmetry.
