US Patent 7973805 Methods and apparatus for invising objects in computer animation

A method for invising objects includes receiving information indicating an intersection between a first object and a second object. Visibility of the first object is modified based on the amount of interpenetration between the first object and the second object. A predetermined threshold may be received. The visibility of the first object may be reduced while the amount of the interpenetration fails to exceed the predetermined threshold. The first object may be made invisible when the predetermined threshold is exceeded.