2009

current frame. Thus, if you set a piece to break at frame 5, the Broken check
box is on at frame 5 and later, and off at frames before 5.
Use Connectivity When on, groups of pieces that are connected to each
other move independently of pieces that they are not connected to. This is
like having multiple fracture objects contained in one fracture helper. The
collision detector determines that two pieces are connected to each other if
their distance from each other is less than the world's
Collision Tolerance on
page 4088.
Break on
Choose the method by which reactor determines whether fracturing should
occur:
■ Impulse When a piece of the fracture object experiences a collision where
the impulse is greater than the threshold specified, it breaks off from the
fracture object. The impulse of the collision is proportional to both the
relative velocity of the collision and the mass of the objects involved in
the collision. The higher the mass of the object that hit the piece, the larger
the impulse.
■ Velocity When a piece of the fracture object experiences a collision where
the relative velocity is greater than the threshold specified, it breaks off
from the fracture object. The size or mass of the object is not be taken into
account.
Energy Loss The amount of extra kinetic energy is lost in the collision due
to the breaking of the fracture bonds. This has the effect of dampening the
collision somewhat and also transferring energy to the remaining, unbroken
pieces of the fracture object. To simulate a brittle object, with maximum
shatter effect, keep this value low. To simulate breakage of a material more
like wood or concrete, use a high Energy Loss value.
TIP Increasing this value can improve the performance and stability of the
simulation.
Display: Show Bounding Box When on, the viewports display a box that
contains all the pieces of the fracture object.
Disabled When on, the Fracture helper has no influence on the rigid bodies
that are part of it.
Reset Default Values Returns the settings to their default values.
4016 | Chapter 16 reactor