2009

Hinge Constraint
Create panel > Helpers > reactor > Hinge
Animation menu > reactor > Create Object > Hinge Constraint
reactor toolbar > Create Hinge Constraint button
The Hinge constraint allows you to simulate a hinge-like action between two
bodies. reactor lets you specify an axis in local space for each body, with a
position and a direction. During the simulation, the two axes attempt to match
position and direction, thereby creating an axis around which the two bodies
can rotate. Alternatively, you can hinge a single body to an axis in world space.
You can also limit the rotation between the attached objects relative to the
hinge axis, allowing you, for instance, to create a door that can open only to
a specified extent. You define this limitation with respect to an axis
perpendicular to the hinge axis for each body.
A Hinge constraint is simulated only if it has the correct number of rigid bodies
attached and is included in a valid
Constraint Solver on page 3945. When not
selected, an invalid Hinge is red in the viewport.
Procedures
To create a Hinge constraint:
■ Choose one of the above options, and then click in any viewport to add
the Hinge constraint.
NOTE The icon’s position has no effect on the constraint’s behavior.
To attach objects to the Hinge:
1 Create the Hinge and the objects to connect using it.
2 On the Hinge's Properties rollout, click the Child pick button, and then
select the object to use as the child object in one of the viewports. By
default, this attaches the constraint so that its axis goes through the child
body pivot point and the axes are aligned with the child body's local
space. The constraint axis is aligned with the child's Z axis, and the
perpendicular axis used for rotation limits is aligned to the child’s X axis.
Constraints | 3969