2009

Convex and Concave Objects
A rigid body primitive is defined as convex if, given any two points inside the
object, you can always go in a straight line from one to the other without
leaving the object. Convex objects include spheres, cylinders, and boxes. For
example, a sphere is convex but a golf ball is concave because of the concavities
(dimples) in its surface. Also, by definition, non-closed meshes (planes, hollow
hemispheres) are always concave.
Convex objects are faster to simulate than concave objects. Because of this,
you should aim to use convex objects as often as possible for simulation.
Treating concave objects as convex for simulation purposes allows you to take
advantage of their faster processing time. This is the default setting for an
object’s simulation geometry (Mesh Convex Hull). If you are unsure whether
an object is convex or concave, you can perform a convexity test on it. With
the object selected, open the reactor - Utilities menu and select Convexity
Test.
You can specify one of the following simulation geometry options to define
how your object will be represented in the physical simulation. To view the
simulation geometry for your objects in the preview, as in the following
examples, select Sim Edges from the Display menu in the Preview Window.
Bounding Box The object is simulated as a box whose extents are determined
by the object’s dimensions.
Rigid Body Properties | 3915