2008

Barycentric Coordinates
Given a triangle between points A, B, and C, each point X on the surface of
the triangle can be represented by a weighted sum of the corners:
X = a*A + b*B + c*C
where a, b, and c are numbers between 0 and 1 and a+b+c = 1.
These numbers are called the barycentric coordinates of the point X. There is
one unique set of barycentric coordinates for each point on the triangle.
Examples
The center of gravity of the triangle is given by the barycentric coordinates
(1/3, 1/3, 1/3): X = 1/3 A + 1/3 B + 1/3 C = (A+B+C)/3.
If one of the barycentric coordinates is zero, the point X must lie on the
opposite edge. For instance:
if a=0, X = b*B + c*C
where b+c=1
This means that X is on the line segment BC.
If a=1, on the other hand, then b=c=0, and X must be exactly the point A.
Behaviors
In
crowd animation on page 4680 , behaviors simulate a range of activities.
Seek, avoid, path follow, surface follow, repel, orientation, scripted, space
warp, surface arrive, wall repel, wall seek, and wander are all behaviors available
in a crowd simulation.
Behaviors let you assign procedural activity types to delegates and objects
linked to delegates. You can associate any number of behaviors with each
Crowd object, and then link delegates and teams of delegates to each behavior.
A specific behavior assigned to a Crowd object belongs only to that crowd; it
cannot be assigned to any other crowds.
7724 | Glossary