9

720 Chapter 13: reactor
Convex objects are faster to simulate than concave
objects. Because of t his, you should aim to use
convex objects a s often as possible for s imulation.
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 geometr y (Mesh Convex
H ull). If you are unsure whether an object is
convex or concave, you can perform a convexity
test on it. With t he 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
thepreview,asinthefollowingexamples,select
SimEdgesfromtheDisplaymenuinthePreview
Window .
Bounding Box—The object is simulated as a b ox
whoseextentsaredeterminedbytheobject’s
dimensions.
B ounding S phere—The object is simulated as an
implicit sphere. The sphere is centered on the
object’s pivot p oint and then minimal ly encloses
the object’s geometry.
Mesh Convex Hull—This is the default option.
The object’s geometry is passed through an
algorithm that creates a convex geometry using
the geometry’s vertices, completely enclosing the
geometry’s vertices. To visualize this, imagine
shrink-wrapping a teapot: The teapot is concav e
but its shrink-wrap forms a convex hull.