Modelling and Simulation of Weft Knitted Fabric Based on Ball B-Spline Curves and
Hooke’s Law
Ke Guo, Xingce Wang*, Zhongke Wu, Ting Zhang, Mingquan Zhou
Beijing Normal University
College of Information Science and Technology
Beijing, China
505290102@qq.com, wangxingce@bnu.edu.cn*, zwu@bnu.edu.cn, elle_zhang@mail.bnu.edu.cn, mqzhou@bnu.edu.cn
Abstract—With the development of computer techniques and
computer graphics, computer aided design (CAD) technology
has been applied widely in the textile printing industry. There
are many good methods for simulating weft knitted fabric;
however, no work on knitted fabric had been performed using
ball B-spline curves. In this paper, we have proposed a novel
algorithm based on ball B-spline curves and Hooke’s Law for
modelling weft knitted fabric in 3D. Ball B-spline curves are
based on B-spline curves that use data balls instead of data
points. By changing the position and the radius of balls of the
ball B-spline curves, we can change the thickness and position
of the yarn. The loop is the basic unit of knitted fabric; it
requires 7 data points to be represented by a ball B-spline
curve, and the model is notably fast. At the same time, the
model maintains both its accuracy and the geometrical and
topological features of the fabric. With VC++ and OpenGL, we
added texture and light to simulate different patterns of weft
knitted fabric in 3D, including stockinette knit, garter knit, 2-2
rib knit, wing knit, heart knit and stripe knit. Because of the
nested structure of knitted fabric, each data point of each loop
has changes in a different way when a force is applied to the
knitted fabric. The deformation and force on the knitted fabric
is modelled using Hooke’s Law, which results in a more
realistic and faster simulation. We use the parameterization
method, and the parameters, such as the radius of ball, the
height of a loop, the number of courses, the number of wales
and the magnitude of the force, are easy to change. This
method is a new means of naturally building and simulating
weft knitted fabric in a CAD system.
Keywords-ball B-spline curve; weft knitted fabric modelling;
Hooke’s Law; three-dimensional deformation; parameterization
method
I. INTRODUCTION
Knitted fabric is widely used in clothing because of its
unique and stretchy behaviour, which is fundamentally
different from the behaviour of woven cloth [1]. Existing 3D
models of knitted fabrics simulate them well, however, some
of them cannot make the fabric flexible. A complex method
and computation should be used to implement a 3D model of
knitted fabric and deform it. Therefore, a large amount of
storage space is necessary, and it takes too long to establish
the model. Our approach develops a method based on ball B-
spline curves that uses 7 points to establish a model of the
basic unit of weft knitted fabric and uses Hooke’s Law to
model deformations.
The main contributions of our approach are:
• The loop is the basic unit of knitted fabric. We
establish a 3D model of a loop that uses only 7 data
points based on ball B-spline curves. The data points
are used for digitizing the knitted fabric and can be
used to model interlocking loops. No work had been
performed on knitted fabric using ball B-spline
curves, which require a minimal amount of data to
establish a 3D model that uses the ball to model the
point. At the same time, the model maintains both its
accuracy and the geometrical and topological
features of the fabric.
• We establish 3D models of fabric created using a
variety of knitting patterns, including stockinette
knit, garter knit, 2-2 rib knit, wing knit, heart knit
and stripe knit. The basic loops used in the different
models of knitted fabric are different. We define the
loops used in different knitting patterns based on
their different geometrical and topological features.
• We visualize the deformation of knitted fabric using
Hooke’s Law. We compute the changes in the data
points when the knitted fabric is under force. Then,
we change their coordinates using Hooke’s Law. We
implement the deformation of stockinette knit under
a horizontal force and when a force is applied to a
single loop.
The reminder of the paper is organized as follows:
Section 2 provides an overview of related work on the
modelling and simulation of knitted fabric. In section 3, we
introduce the knitting principles of weft knitted fabric and
the method of ball B-spline curves. We define the basic loop
of knitted fabric in section 4, and then, we model different
types of knitted fabric. The fabrics are deformed in Section
5. Finally, we present the conclusions in Section 6.
II. R
ELATED WORK
At present, many achievements have been made in
research on the modelling of weft knitted fabric. Xiaoli Shi
[2] established a 3D model of a loop based on Pierce’s 2D
loop model and used an illumination mode to enhance
realism. Su Liu [3] used parametric equations to define a
spatial arc and presented a 3D model based on the curves.
This method modelled the knit structure well in 3D.
However, its visual effect was singular. Kehe Zhang [4]
established 3D models of stockinette knit, garter knit and 2-2
rib knit using the finite element method (FEM). Using this
method, a general mathematical model of the structure of
weft knitted fabric was created. Chang Qu [5] created a
2015 International Conference on Cyberworlds
978-1-4673-9403-1/15 $31.00 © 2015 IEEE
DOI 10.1109/CW.2015.38
86
2015 International Conference on Cyberworlds
978-1-4673-9403-1/15 $31.00 © 2015 IEEE
DOI 10.1109/CW.2015.38
86