Interpolation-Based Animation - Computer Animation: Algorithms and Techniques - page 120

Displacement of seed vertex

Attenuated displacement propagated to adjacent vertices

FIGURE 4.8
Warping of object vertices.

expensive, function uses the minimum distance traveled over the surface of the object between the seed
vertex and the vertex to be displaced.
Attenuation is typically a function of the distance metric. For example, the user can select a function
from a family of power functions to control the amount of attenuation [ 28 ]. In this case, the minimum of
connecting edges is used for the distance metric and the user specifies the maximum range of effect to
be vertices within n edges of the seed vertex. A scale factor is applied to the displacement vector
according to the user-selected integer value of k as shown in Equation 4.1 .

0
@

1
A

kþ 1

i
n þ

SðiÞ¼ 1 k 0

1

0
@

0
@

1
A

1
A

(4.1)

kþ 1

i
n þ

¼ 1 k < 0

1