8

Flex Modifier 685
8.
On F orces and Deflectors rollout > Forces
group,clicktheAddbutton,andthenselectthe
Wind gizmo in the viewports.
9. Click Play.
Thesphereundulatesinthewind. The
Advanced Parameters rollout > Reference
Frame setti ng determines the f r ame where the
force(s) in the list take effect.
You can also use this example to see how the
Chase Springs option works.
10. Turn off Chase Springs and click Play
again.
The sphere keeps mov ing in the direction the
wind is blowing without "bouncing" back.
That’s because the chase springs, which attempt
to return the object to its original shape, are no
longer in effect.
To add custom springs:
1.
Apply F lex to an object and go to the Weights &
Springs sub-object level.
The Flex vertices appear at object vert ices in
the viewports.
2. In the Advanced Springs rollout, turn on Show
Springs.
3. Click the Options button and in the Spring
Option dia log (page 1–692)
,choosehowyou
want to add springs. Exit the Spring Option
dialog.
4. Select vertices according to the options.
For instance, if you want to add one Hold
Shape spring between two vert ices, select both
vertices.
5. Click Add Spring.
The new spring or springs appear. Edge springs
are blue and Hold Shape springs are red.
Ex ample: To create a s winging r ope:
1.
UseCreatemenu>SpaceWarpstoaddaDrag
and a Gravity space war p in the Top view por t.
2. Use Create menu > Shapes > Line to create a
line with ten vertices space d evenly in the top
view por t.
3. IntheModifypanel,turnonVertexsub-object
and select all the vertices except the first vertex.
4. Add the Flex modifier.
5. In the modifier stack view, open Weights and
Springs sub-objects.
6. Tu rn off Use Chase Springs.
7. Turn off Use Weights.
8. Set the solver to Runge-Kutta4.
9. Set Samples to 5.
10. In a viewport, select a ll the p oints on the spline.
11. In the Advance Springs rollout, click the Option
button.
12. In the dia log, turn on Hold Ed ge Length
Springs and click OK.
13. Click Add Springs.
14. On the Forces and Deflectors rollout, add
Gravity and Drag in the Forces group.
15. Click Play.
The spline resembles a swinging rope.
Ex ample: To creat e cloth dr aping on a sphere:
1.
UseCreatemenu>SpaceWarpstoaddaDrag
and a Gravity space war p in the Top view por t.
2. UseCreatemenu>SpaceWarps>Deflectors
>SDeflectortocreateasphericaldeflector.
Set B ounce to 0 and Friction to 100. Place the
deflector below Z=0.
3. UseCreatemenu>Geometry>Standard
Primitives > Plane to create a 20 x 20 plane
intheTopviewport. Itshouldbeabovethe
spherical deflector.