9

Flex Modifier 693
7.
Open the Flex modifier hierarchy in the stack
display, and click Weights & Springs.
This enables modification of the Weights &
Springs sub-object settings.
8. InthePaintWeightsgroup,turnonPaint.
9. In the Left viewport, paint on t he lower part
of the sphere.
Thevertexcolorchangesasthevertexweight
changes. Yel low vertices are more rigid, blue
vertices ar e less rigid.
Note: You can change Flex vertex colors
through Customize menu > Customize User
Interface > Colors > Geometry > Subselection
Hard/Medium/Soft.
10. Click Play.
Thespherewobblesononesidemorethanthe
other.
If the Strength setting in the Paint Vertex group
is a positive value, you paint rigidity. If the
values are negative, you paint flexibility.
Paint with negative numbers for Strength to
reverse the effect.
Example: To use wind a s a force:
1.
IntheTopviewport,createasphere.
2. On the Create panel, click Space
War ps, and then, if necessary, choose Forces
from the drop-down list.
3. Click Wind, and then click and dr ag in the
Front viewport to create a wind gizmo .
4. On the Wind Parameters rollout, set Strength
and Turbulence to 4.
5. Select the Sphere.
6. Apply the Flex modifier .
7. On the Modify panel > Parameters rollout, set
Samples to 1.
8. On Forces and Deflectors rollout > Forces
group, click the Add button, and then select the
Wind gizmo in the viewports.
9. Click Play.
Thesphereundulatesinthewind. The
Advanced Parameters rollout > Reference
Framesettingdeterminestheframewherethe
force(s) in the list t ake effect.
Yo u c a n a l s o u s e t h i s e x a m p l e t o s e e h o w t h e
Chase Springs option works.
10. Turn off Chase Springs and click Play
again.
The sphere keeps moving in the direction the
wind is blowing without "bouncing" back.
That’s b e cause the chase springs, which attempt
to return the object to its original shape, are no
longer in effect.
To add custom springs:
1.
Apply Flex to an object and go to the Weights &
Springs sub-object level.
The Flex vertices appear at object vertices in
the view ports.
2. In the Advanced Springs rollout, turn on Show
Springs.
3. Click the Options button and in the Spring
Option dialog (page 1–700),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 vertices, select both
vertices.
5. Click Add Spring.
The new spring or springs appear. Edge springs
are blue and Hold Shape springs are red.