Design Animation > Design Animation > Creating an Animation > Defining Bodies > About Bodies
  
About Bodies
A body is made up of one or more parts that do not move relative to each other. By default, bodies in Design Animation are created following the Mechanism Dynamics rules, parts with a constraint between them are placed in a single body. For more information on bodies, search the Help Center.
Keep the following points in mind when creating body definitions:
• Body definitions created in Design Animation will not transfer to Mechanism Dynamics.
• Depending on the constraints used to create your assembly, you may want to redefine the model using One part per body or Edit.
• If a body definition has been edited and saved in a subassembly, you cannot edit the body in a higher level assembly. You must edit the body in the subassembly, then save it.
• If a subassembly body configuration is not saved, a default body definition is automatically created. The default definition can then be edited.
When you click Body Definition, the Bodies dialog box opens:
• Click New or Edit to open the Body Definition dialog box and create a new body or edit an existing one. Any parts added to a body are removed from the bodies that previously contained them. All parts automatically belong to the ground body if they were assembled using user defined constraints.
• Click Remove to remove a selected body. Other parts in that body are moved to the ground body.
• Click One part per body to create bodies using the one part per body rule. All connections are retained.
 
* Use one part per body with caution when defining large assemblies because each part in the assembly becomes an individual body. You will also have to redefine the ground body.
• Click Default bodies to revert to the original body definitions. This option causes the assembly to automatically regenerate, and then reassign parts to bodies. Any body definitions already created are ignored.
 
* Best practice is to use default bodies when defining bodies in your assembly. If you do not, regeneration may fail or parts may be placed in different locations when you open or regenerate the assembly in another mode.