2009

World rollout > Fracture Penetrations group
Several additional values govern fracture behavior. These are global in that
they apply to every rigid body added to a Fracture object, and are found in
the Utility panel > reactor > World rollout.
These values control the behavior of penetration depth collision detection
and response, and apply only to objects that are included in a Fracture helper.
Separation Time Forces are applied to penetrating bodies that are strong
enough so the bodies become separated within the time specified. To simulate
an explosion effect, make this value very small and reduce the Velocity Cap
value.
Velocity Cap reactor won't apply penetration recovery forces if they cause
the relative velocity between two penetrating bodies to exceed the specified
value.
Scale Tolerance The collision tolerance for bodies that use the penetration
depth algorithm is determined by multiplying the Collision Tolerance value
on page 4088 by the value specified. If this value is negative, the collision
tolerance will extend inside the bodies, effectively shrinking the collision
geometry.
For more information about using these values, see the
Fracture Tips on page
4017 topic.
Fracture Tips
After you procedurally slice up an object for fracture, the new pieces fit snugly
among each other. When one piece breaks loose after a fracture event, it might
be in contact with other pieces that are still part of the non-fractured body.
This can throw the broken piece into unstable oscillations against two or more
opposing pieces. The result is a chain-reaction throughout the fracture body,
with all the pieces flying off into space. It might appear as though some of
the pieces simply wink out of existence. Unlike normal rigid bodies in reactor,
reactor Objects | 4017