2009

large Repel fields so that they can smoothly avoid each other while maintaining
a comfortable margin of error. Repel forces prevent intrusion from all sides,
regardless of the direction of travel. Thus even animals that rely mainly on
Steer to Avoid will also need some degree of Repel avoidance to maintain
spatial separation when they are moving through dense traffic. The forces of
Repel avoidance are always directed uniformly outward in a spherical shape.
Use Vector Field avoidance for cases where crowd members must avoid hitting
the more complex shapes of arbitrary 3ds Max objects. The outward forces of
the Vector Field avoidance can constructed to form the shape of any object.
For example, suppose you want to animate a school of fish swimming around
a sunken ship. In this case, a vector field can be created so that it extends the
shape of the ship into the surrounding space. The field is computed by scan
converting the ship's surface normals into a 3D lattice that surrounds the ship.
These normals will extend into space as "beacons" in the 3D lattice, telling
the fish how to best swim away from the shape of the ship. As the fish enter
the space of the vector field lattice, they can be precisely repelled along an
avoidance force directed away from ship's surface.
NOTE In the explanations that follow, the word "target" is used to refer to the
object or objects to be avoided.
4868 | Chapter 17 character studio