Adobe Director Basics

ADOBE DIRECTOR BASICS
3D: Controlling action
Get-only properties
A D6Joint object has five properties whose value is set at the moment that you call createD6Joint(), and which cannot
be changed later. Attempting to alter the value of these properties will lead to a script error.
constraint.name
d6joint.objectA
d6joint.objectB
constraint.constraintType (D6Joints are a type of constraint, just like linear and angular joints. The
constraintType for D6Joint is #d6joint)
Anchor properties
A D6Joint object has three properties that define the mutual frame of reference of the joined rigidBody objects.
d6joint.globalAnchor
d6joint.localAnchorA
d6joint.localAnchorB
The Physics simulation uses world space as a frame of reference for all objects that it controls. When you create a
D6Joint, you define a position in world space as the globalAnchor point for the joint. The two rigidBody objects now
share a mutual point of reference: the globalAnchor. Each of the rigidBody objects joined by the joint converts that
worldPosition point into its own local frame of reference. These references are stored in the localAnchorA (for the
first named rigidBody) and localAnchorB (for the second rigidBody).
If the rigidBody objects now move together, with respect to the world, the worldPosition of their globalAnchor will
change. It is “global” only in the sense that it is shared by both rigidBodies in the joint. Each rigidBody will maintain
its own position and orientation relative to the shared globalAnchor point.
If you alter the values of localAnchorA or localAnchorB the associated rigidBody will move to a new position with
the respect to the mutual globalAnchor point.
If you change the value of the globalAnchor the values of localAnchorA or localAnchorB will update to reflect the
current positions of the two rigidBody objects with respect to the new globalAnchor point.
Note: If you create a joint with only one rigidBody and VOID as the other party to the joint, then changing the
globalAnchor point will affect the center of rotation of the sole rigidBody.
Freedom properties
You can set the freedom of each of the six types of motion available to a D6Joint. The following properties can take the
values #locked, #limited, or #free:
d6joint.axisMotion: refers to linear motion along the main zAxis
d6joint.normalMotion: refers to linear motion along the xAxis
d6joint.biNormalMotion: refers to linear motion along the yAxis
d6joint.twistMotion: refers to angular motion around the main zAxis
d6joint.swing1Motion: refers to angular motion around the xAxis
d6joint.swing2Motion: refers to angular motion around the yAxis
See “D6Joints” on page 338 for a demonstration of these different motions.
Last updated 8/26/2011
345