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766 Chapter 13: reactor
Ang Speed—
The target angular velocity that the
motorattemptstoachievefortherigidbody. It
is specified in radians per second, so the default
value of 3.14 (pi) results in 180 degrees of rotation
persecondorhalfarevolutionpersecond.
Gain—The maximum angular impulse that the
motor can apply to the rigid body in order to
achieve the target velocity.
Rotation Ax is—The local axis for the rigid body
about which the motor applies impulses. This axis
has a visual representation when the motor helper
is selected.
Disabled—When on, the motor is not added to the
simulation.
Size—Thesizeoftherotationaxisintheviewport.
Reset Default Values—Returns Ang Speed, Gain,
and Rotation Axis to their default values.
Toy Car
Create panel > Helpers > reac to r > Toy Car
Menu bar > reactor > Create Object > Toy Car
reactor toolbar > C reate Toy Car button
ThereactorToyCarisaquickwaytocreateand
simulate a simple car without having to set up each
constraint separately.
The Toy Car helper lets you choose a chassis and
wheelsforyourcar,tweakvariousproperties
such as the strength of its suspension, and specify
whether you would like reactor to turn its w heels
during the simulation. reactor then sets up all the
necessary constraints to simulate the car.
A Toy Car is simulated if it has a rigid body
assigned as a chassis and at least one rig id body
assigned as a wheel. When not selected, an invalid
Toy Car helper is red in the viewport.
Procedures
To set up a toy c ar, follow these procedures in
order,andmakesurethecarhasasurfacetotravel
on, such as a level plane. For getting started, we
suggest you use Icon Or ientation and ig nore the
procedure about Common Local Orientation.
To create a Toy Car helper:
• Chooseoneoftheabovemenuoptions,and
then click in any view port to add the Toy Car.
Note: Theicon’sinitialpositionhasnoeffect
on the car’s behavior.
To set up the r igid bodies f or a Toy Car :
1.
Create and p osition the rigid bodies you want
to connect using the Toy Car helper.
A toy car must hav e a chassis and at least one
wheel.
2. Use the Rigid B ody Properties dialog to assign
amassvaluetoeachcarelement.
TheMassvaluesyouspecifyaffecthowthetoy
car behaves. Ideally, the mass of the chassis
should not be much greater than the total wheel
mass, and the density of the bodies should be