Displaying the Assembly Mass Properties

	This task shows you how to display the assembly mass properties.
	The mass property of any assembly component is available from its `Properties`, in the `Mechanical` tab. The mass property is also available for component in `Visualization` mode and you can refine the mass to the main body or all the bodies of a Part component. The mass property is set according to the part material. If any material has not been defined, a density of 1 is taken into account. Density can be saved into cgr documents, see Cgr Management for Density.
	Be sure that you are working in `Design` mode, see Cache Management for CATProduct and CATProcess Document. Open the Assembly_01.CATProduct document.
	Right-click `Assembly_01` in the specification tree and select `Properties...` from the contextual menu.
	The `Properties` dialog box appears.
	Select the `Mechanical` tab.
	Three main properties are displayed: Characteristics: Volume Mass Surface Inertia center Inertia matrix
	The `Only main bodies` option allows you to take into account only the main body of the related parts in the assembly, to determine the mechanical properties. If `Only main bodies` option is selected then it will remain activated until current CATIA session is on, and for a new session it will be cleared.

	Redo the two previous steps, working with the `Visualization` mode.
	The same characteristics and option are displayed. Note that values can be different because the geometry is not exact in `Visualization` mode, and has been approximated. A message is displayed in this case. The smaller the sag (3D Accuracy) is, the smaller will be the error range between the results in `Visualization` mode and in `Design` mode.

	Click `OK`.