Collections are also measurable, since they might contain measurable objects.
Measurable objects can have their measurable property individually enabled or disabled (enabled by default for non-pure shapes). This can be set in the object common properties or through the simSetObjectSpecialProperty API function.
Additionally, measurable objects can have their measurable property overridden depending on their related model properties (if they are part of a model). Refer to the model dialog for more information.