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666 Chapter 12: Animation
17.
Turn on Up d ate D isplay w ith Solve, and then
click Solve.
In the viewports the objects fall and collide
with each other and the ground plane.
18. Turn on the Auto Key button , move the time
slider to frame 15, and then select and move the
"ground" box upward along the Z axis.
The ground will "move" during the simulation.
19. Click Solve.
The keyframed "ground" b ox moves up
and collides with the boxes. The ability of a
keyframedobjecttobepartofasimulationis
one of the useful features in 3ds Max. You could
use this capability to strike a ball with a bat,
for example.
For further experimentation, create a spring
object in Create panel > Geometry > Dynamics
Objects and attach the ends of the spring
object to two of the b oxes and then solve the
simulation. The spring will stretch and follow
the b ouncing boxes.
You can use the space warps in Create panel
> Space Warps > Dynamics Int erface, such as
SDynaFlect (Spherical Dynamics Deflector) to
cause a par ticle stream to "push" an object in a
dynamics simulation.
To remove the dynamics tracks and restore the
original a nimation tr ack s in Track View:
When you solve a dynamics simulation, 3ds Max
creates a list controller that holds both the
generated dynamics keys and the original keys.
This lets you easily restore the orig i nal keys. Undo
is not supported by Dynamics.
To layer simulations, reverse this method. In other
words, after you’ve solved the first simula tion,
copy its controllers to the old tracks, and then
set up the next level of the simulation. T he new
simulation wi ll base its actions on the previous one
instead of overwr it ing it, as it normally does. You
can repeat this as many times as you like to layer
simulations
ad infinitum
.
Since U ndo is not supported b y Dynamics, you
can also use Hold and F etch in its place.
1. In Track View, open the Position track for an
object animated by a dynamics simulation.
2. Select the Old Position track, and click Copy
Controller on the Track V iew toolbar (the
second button from the left).
3. Select the Position track (the parent), and
click Paste Controller (to the right of Copy
Cont roller).
4. Click OK in the Paste dialog.
The two sub-tracks and the Position parent
track are replaced by a single Position track
containing the original keys that were in the
Old Position t rack.
Repeat the above steps w ith the Rotation track.
To set up dynamics:
1.
Assignmaterialstotheobjectsincludedinthe
simulation and adjust the surface characterist ics
in the Dynamics Properties rollout of the
Material Editor. (For a bouncing ball, you’d use
this to create a rubber-like surface.)
2. If you’re using a linked hierarchy, set t he Move
andRotatelocksintheHierarchy/LinkInfo
panel to limit the motion and rotation of the
linked objects.
3. Create space warp effects in the scene where
needed. (For a bouncing ball, you’d need a
Gravity space warp.)
4. Use the Dynamics utility to create a new
simulation. Specify which objects are included
in the simulation, which effects influence which
objects, and which objects should collide w ith
which. (For the b ouncing ball, the ball and the
floor are in the simulation because one collides
w ith the other. You assign the b all the floor to