9

Toy Car 769
Icon Orientation—
The Toy Car icon’s initial
orientation provides the directions of the wheels’
spin and suspension axes. Each spin axis is
aligned with the icon’s X axis and pass through the
relevant wheel’s pivot point. The suspension axes
are alig ned with the icon’s Z axis, and also pass
througheachwheel’spivotpoint.Thewheels’own
local orientations are unimportant.
Note: Animating the orientation of the Toy Car icon
has no effect on the direct ion of motion during the
simulation; reactor uses only the orientation at the
start of the simulation.
Common Local Orientation—With this option, you
align the bodies’ local spaces in world space, and
specify the Spin and Suspension axes relative to
this common orientation. The orientation of the
rigid bodies in world space before simulating is
unimportant.
This mea ns, for instance, that you can set up your
car with its wheels turned sideways and they still
spin around the correct axes when simulating.
This option allows you to change the spin and
suspension axes separately. By default, the spin
axes are aligned with the wheel and chassis’ local X
axes, and the suspension axes with their Z axes.
Allow Wheel Penetrat ion—When on, reactor
disables collision detection between the chassis
and the wheels.
Spi n Wheel s—When on, the car’s wheels to spin
during the simulation and an arrow appears on
the Toy Car viewport icon showing the direction
of motion.
•
Ang S peed—The target angular velocity that
reactorattemptstoachieveforthewheelswhen
Spin Wheels is on. It is specified in radians per
second, so the default v alue of 3.14 (pi) results
in 180 degrees of rotation per second or half a
revolution per second.
•
Gain—The maximum angular impulse that
reactor can to the wheels in order to achieve the
target velocity.
Disabled—When on, reactor removes the Toy Car
helper from the simulation.
Display Size—The size of the Toy Car helper icon as
displayed in the viewport.
Reset Default Values—Returns the Toy Car
parameters to their default values.
Havok 3 Wh eel Params rollout
These parameters apply only w hen the s imulation
engine is Havok 3, and reflect the implementation
of a subset of Car-Wheel constraint parameters in
the Toy Car object in Havok 3.
These parameters replicate the Car-Wheel
constraint par ameters of the same names (page
2–761).