Click Tools > Collision Detection > Edit Collision Sets.
Click the Type Filter tab.
In the Collision set name box, select the collision set to edit.
Edit the Default Collision Set.
To define a new collision set, type a name in the Collision set name box. Single tick marks ( ' ) are not allowed in the name.
Under Collision types, select All types or Selected types.
If you choose Selected types, you can select specific filters for the collision detection process. The software only reports the types of collisions that you specify. For more information on filter options, see Type Filter Tab (Edit Collision Sets Dialog Box).
To delete a collision set, select a collision set name in the Collision set name box, and then click Delete, or press DELETE on the keyboard.