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helper, can move independently as separate fracturable objects. As a result,
you can get the effect of multiple fracturable objects in a single Fracture helper.
After a fracture event occurs, reactor once again analyzes this connectivity
graph to create new chunks if they exist. If you see floating disconnected
bodies moving strangely because they are invisibly still part of a larger fracture
object, be sure to turn on connectivity. A body is considered to be in contact
with another body if the closest distance between them is less than the collision
tolerance.
To allow the fracture feature to work reasonably well, reactor uses a special
collision detection technique: penetration depth calculation. Unlike normal
rigid bodies in reactor, bodies that are part of a fracture helper are allowed to
continue to collide with each other, even when they are in a interpenetrating
state. To see how the non-fracture bodies are treated during collision detection,
see the
Fracture Tips on page 4017 topic. Penetration depth calculation, especially
in the context of the simulation paradigm used in reactor, is computationally
expensive, so you might notice slower performance when the fracture bodies
are penetrating each other. Stability in these cases can also become an issue.
reactor provides a number of techniques for getting your fracture simulation
to behave more realistically If you find that it is unstable. For instance, the
fractured object might appear to explode after a single piece breaks loose. You
can find these in the
Fracture Tips on page 4017 topic.
Procedures
To create a Fracture helper:
■ Choose one of the above menu options, and then click in any viewport
to add the Fracture helper.
NOTE The icon’s position has no effect on the fracture object's behavior.
To add rigid bodies to a Fracture helper:
1 Create a Fracture helper in the scene and some objects to use as rigid
bodies.
You can add rigid bodies to the helper in two ways: by picking or by using
a selection list.
4012 | Chapter 16 reactor