9

Preview & Animation Rollout 807
Inter face
Start Frame—When creating a world to be
simulated or previewed, reactor needs to access the
objects in 3ds Max at a fixed point in time. This
parameter defines this point in time (in 3ds Max
frames). Initial shapes, positions and velocities
are taken from the actual shapes, positions
and velocities of the objects in the scene at this
particular f r ame. When creating an animation,
keyframes are created starting from this frame to
the E nd Frame time.
End Frame—The last frame to simulate. When
reactor creates an animation, it generates
keyframes from the Start Frame time to this frame.
Fr ames/K ey—The number of frames for every
keyframe that reactor creates (time step). For
example, a value of 2 will create a keyframe every
other frame. Increasing this value forces reactor
to take bigger time steps, potentially reducing the
accuracy of the simulation; you mig ht need to then
update t he Substeps/Key setti ng accordingly (see
follow ing).
Substeps/K ey—The number of reactor simulation
substeps per keyframe (that is, per time step).
The higher this value, the more accurate the
simulation will be, although it will also require
more computation to simulate. For information
about time steps and substeps, see Time Steps
(page 2–709).
Time Scale—This p arameter maps between
time in t he simulation and time in 3ds Max.
Changing the value lets you slow down or speed
up the animation. Values less than 1.0 produce
slow-motion animations, while val ues greater than
1.0 produce sped-up animations.
Create Animation—Runs the simulation and creates
keyframes, starting at Start Frame and ending at
End Frame.
Update V i ewpor ts—When on, updates the scene in
the viewports as the animation is created.
Create Lis t/Layer —When on, creates a List
controller (page 2–342) (unless one is already
present) for the position and rotation tracks of
those rigid bodies using Position/Rotation/Scale
transform controllers. A new subcontroller is
added to the List controller to hold the keys created
by reactor. This new controller is weighted to 100,
while the previous controllers are weighted to 0.
In the special case of rigid bodies belonging to a
character studio Biped (page 2–843),anewbiped
layer is created every time a reactor animation is
generated.
Prev iew A nimat ion—Previews the simulated scene
in the Preview Window (page 2–815).