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764 Chapter 13: reactor
Child—
Displaysthenameofthesecondrigidbody
attached to the constraint. You assign the child
object by clicking this button an d 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).
Breakable group
Breakable—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 Constraints
(page 2–735).
Display group
Size—Letsyouchangethesizeoftheconstraint
space display in the viewport.
Reset Default Values—Returns the constraint’s
parameters to their default values.
reactor Objects
Plane
Create panel > Helpers > reactor > Plane
Menu bar > reactor > Create Object > Plane
reactor toolbar > Create Plane button
ThereactorPlaneobjectisatypeofrigidbodythat
acts as a fixed, i nfinite plane in the simulation. It
shouldn’t be confused with the standard 3ds Max
plane, which can also be used as a rigid body
provided its sim ulation geometry property (page
2–719) is set to Concave Mesh.
Like other rigid bodies, the Plane can have display
proxies assigned to it and can be cont ained in a
compound rigid body. You can also assign friction
and elasticity values to it. However, it is always
fixed in the simulation (the Mass (page 2–718) and
Unyielding (page 2–718) proper ties are ignored).
The reactor Plane acts in only one direct ion, as
show n in the viewpor t by an arrow pointing away
from its solid surface. This means that rigid bodies
approaching the plane f rom the "wrong" direction
pass through it. You can, of course, also use two
opposing planes.
The reactor Plane a s rendered in a viewport