2009

Assign Object Collisions Displays a subdialog that lets you choose which
objects in the scene are considered for collision with the current object. This
dialog works the same as the Assign Object Effects dialog, except that it lists
only objects in the simulation. Objects included for collision in this dialog
can collide with the current object.
NOTE For every potential collision, you should explicitly specify both colliding
objects. For example, if you specify that Box01 is to collide with Box02, you should
also specify that Box02 is to collide with Box01. This is primarily for keeping track
of your simulation; if you specify the collision for only one object, it works for the
other as well. While it is not necessary to specify that Box02 collides with Box01,
this is the only way to update the Assign Object Collision list for Box02.
The Assign Object Effects dialog functions similarly to the
Edit Object List
dialog
on page 3873.
Collision Test group
Specifies the type of boundary used for collision testing.
Box A bounding box is used to test collision. This is the fastest method. If
your object is a box or close to a box shape, this option is both fast and
accurate.
Cylinder A cylindrical form is used to test collision. The "height" axis of the
cylinder is aligned with the local Z axis of the object.
Sphere A spherical form is used to test collision.
Mesh Uses the surface of the object to calculate the collision. This option is
the most accurate, but also takes far longer to calculate than the previous three
methods. Use this only when your object is too complex to work properly
with the first three options.
Recalculate Properties group
Specifies when to recalculate the properties of an object that changes over the
course of the animation. Specifically, the properties refer to the mass moment
of the object. The mass moment of an object can be defined as the measure
of how the mass in an object is distributed with respect to the center of mass
of that object. Altering the mass moment changes the way an object responds
to torque. If your object is changing shape over time, and you want to take
this into account for the simulation, you should recalculate the properties.
Never No calculation is performed beyond the first calculation for the
dynamics solution.
3870 | Chapter 15 Animation