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constraint you use, you can hinge objects together, attach them together with
springs that will snap back if the objects are pulled apart, or even simulate the
movement of a human body joint. You can constrain objects to each other
or to points in space.
This section shows you how to work with constraints in reactor. It includes
the following sections:
Constraint Concepts on page 3926
Simple Constraints on page 3930, which includes the following topics:
■ Spring on page 3930
■ Linear Dashpot on page 3934
■ Angular Dashpot on page 3939
Cooperative Constraints on page 3943, which includes the following topics:
■ Constraint Solver on page 3945
■ Rag Doll Constraint on page 3948
■ Hinge on page 3969
■ Point to Point on page 3975
■ Prismatic on page 3982
■ Car-Wheel on page 3988
■ Point to Path on page 3995
Constraint Concepts
This section introduces some common concepts that you'll need to understand
to work with any of the reactor constraint types.
Constraints, Simple Constraints and Cooperative Constraints
You use constraints in reactor to specify limitations in the movements of
objects. Without constraints, the movement of objects could be limited only
by collisions and deformations. This is the case in the real world: For example,
a door's movement is limited by a set of pieces that form a hinge; the collisions
between those objects limit the movement of the door. The motion of two
3926 | Chapter 16 reactor