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750 Chapter 13: reactor
Thereafter the button displays the name of the
parent bo dy.
Child—Displaysthenameofthesecondrigidbody
attached to the Hinge. You assign the child object
by clicking this button and then selecting a rigid
body from any viewport.
Align Spaces To—Use these options to align the
bodies’ local constraint spaces. You can find
out more about each option in Working With
Constraint Spaces (page 2–726).
Lock Rel a ti v e Tr a ns fo r m—When on, the relative
transform b etween the child and parent constraint
spaces is locked: If you move either space i n the
viewport, the other space moves and rotates along
with it, and vice-versa.
Strength group
Strength/Tau—Govern the impulses applied to
the constraint’s bodies in order to maintain the
constraint, and so how strongly the constraint
works to restr ic t their movement. You can find out
more about these parameters in Strength and Tau
(page 2–735).
Limited group
Limited—When on, limits the rotation about the
hinge axis between the attached objects. When
this value is true, the child object will only be free
to rotate relative to the parent within the range
specified by the Min Angle and Max Angle values.
You can also specify a friction value for a limited
Hinge.
Min Angle—The minimum rotation the constraint
allows between the two hinge spaces. For example,
if Min Angle is –5.0 then the child body cannot
rotate more than 5 degrees counter clockwise
about the hinge axis relative to the parent body.
Max Angle—Themaximumrotationtheconstraint
allows between the two hinge spaces. For example,
if Max Angle is 5.0 then the child body cannot
rotate more than 5 degrees clockwise about the
hingeaxisrelativetotheparentbody.
Fr iction —The level of friction applied to the objects
astheytrytorotateaboutthehingeaxis.Itisonly
applied to limited Hinges.
Breakable group
B r ea kab l e—When on, the constraint is breakable.
If its breakable limits are exceeded during
simulation, it ceases to exert impulses on the
attached objects. You can find out more about
breakable constraints in Breakable Constrain ts
(page 2–735).
Display group
Size—Lets you change the size of the Hinge limit
display in the viewport.
Reset Default Values—Returns the Strength, Tau,
MinAngle,MaxAngle,Friction,Linear,Angular,
Threshold, and D isplay settings to their default
values.
Point-Point Constraint
Create panel > Helpers > reactor > Point-Point
Menubar>reactor>CreateObject>Point-Point
Constraint
reactor toolbar > C reate Point-Point Constraint button
The Point-Point (point-to-point) constraint lets
you attach two objects together, or an object to a
point in world space. It forces its objects to try
to share a common poin t in space. The objects
can rotate freely relative to each other, but always
have the attachment point in common. When you
set up the constraint, the poin t is defined in the
object space of each object involved. During the
simulation the constraint tries to apply forces to
the objects so that the two pivot points defined by
the two objects match.