8

574 Chapter 8: Modifiers
Left: U and V Bend=50, simulating a burlap material
Right: U and V Bend=2.5, simulating silk or other light fabric
UB-Curve/VB-Curve—Resistance to bending as
the fabric folds. The default v alue of 0 sets the
bend resistance to be constant. A setting of 1
makes the fabric ver y resistant to bending as the
angle between triangles approaches 180 degrees.
You never want two adjacent triang les to pass
through each other, so you can increase this value
to prevent this from happening.
By default, the U B-Curve and V B-Curve
parameters are lo cked together so that changing
one sets the other to the same value. You can set
different values for the two only when
Anisotropic
is off. It is recommended to do this only for
Garment Maker (page 1–587) objects.
UStretch/VStretch—Resistance to stretching. T he
default value of 5 0.0 is a reasonable value for most
typesofcloth.ALargervaluewillbestiffer,while
a smaller one will be stretchy like rubber.
By default, the U St retch a nd V Stretch pa rameters
are locked together so that changing one sets the
other to the same value. You can set different
values for the two only when
Anisotropic is off.
Itisrecommendedtodothisonlyfor
Garment
Maker (page 1–587)
objects.
Shear—Resistance to shearing . Higher values
result in stiffer cloth fabrics. Shear defines how
much the individual triangles can deform. If you
were to lay the edges of the triangle out i n a strait
line this value would represent how long this line
can stretch out to. With a high value this length
will only be the sum of the length of all of the
sides at rest. A low value wil l al low this leng th to
be greater then t hat off a ll of its sides at rest. This
length of stretched sides is not on a one to one
basis. One side of the polygon m ay stretch more
thenanotheraslongasthetotalshearvalueisnot
exceeded.
Density —The weight of the cloth per unit area (in
gm/cm2). Higher values mean heavier cloth like
denim. Use smaller values for lighter cloth like silk.
Thickness—Defines t he virtual thickness of a
fabric for the purp ose of detecting cloth-to-cloth
collisions. This value is irrelevant if cloth-to-cloth
collisions are disabled. Larger values keep the
cloth separated by greater distances. Be careful
not to use too large or small values in this field.
Very large values wil l interfere with the natural
behavior of the cloth. Very small values will cause
the simulator to take too long to calculate. This
distance is measured in cm (centimeters) and
should be smaller than the size of the triangles that
make up the cloth object. A setting of 0.0 w ill let
Cloth automatically assign a reasonable value for
thickness.
Left: The top piece of clot h with a Thickness of 0
Right: Thickness of 9
Repulsion—The amount of force used to repel
other cloth objects. This value is ir relevant
if cloth-to-cloth collisions are disabled. The
simulator will apply a repulsion force scaled by
this value to keep the cloth from coming in contact