Adobe 65036570 - Director - PC User Manual page 430

• Angular joint or Constraint
•
Raycasting
Rigid Bodies
The objects created in the physics world are rigid bodies that do not change shape. The geometry of the bodies does
not vary for each advance of time in the simulation.
The physics world provides methods to create a static or a dynamic rigid body.
A proxy shape has to be specified for each rigid body for approximating the geometry during the physics simulation.
The supported shapes are axis-aligned bounding box (AABB), sphere, convex hull, and a static concave shape.
Rigid body Properties
The rigid body has properties like mass, position, orientation, velocity, and momentum.
All these properties have a default value of zero. Properties like mass have to be set in order to achieve proper
simulation.
Rigid Body Methods
The rigid body has methods to apply force, torque, and impulse.
Spring
A spring is a constraint that maintains its original rest length on compression and expansion.
A spring can be created between two rigid bodies (static or dynamic), or between a point in the world and a rigid
body. The bodies to which the spring is attached can be changed after creation of the spring.
The physics world provides properties to set/retrieve the rest length, stiffness of the spring, and the damping coeffi-
cient. Flags are provided to enable/disable the compression and expansion force acting on it.
Linear Joint or Linear Constraint
When you apply a linear joint or linear constraint to an object, it is free to move in a linear fashion. The angular
movement is constrained.
The physics world uses createLinearJoint() method to create a linear joint that takes the orientation to be constrained
as the parameter. The stiffness and coefficient of damping for the constraint is specified in the constraint descriptor
object.
Angular Joint or Angular Constraint
When you apply an angular joint or angular constraint to an object, it is free to move in an angular fashion. The linear
movement is constrained.
The Physics world uses createAngularJoint() method to create the angular joint that takes the length to be
constrained as the parameter. The stiffness and coefficient of damping for the constraint is specified in the constraint
descriptor object.
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User Guide