Body modifiers use the 3-dimensional (3D) geometry of an object, such as a mass element or a mass group, to add to, subtract from, or completely replace one component in a wall. If the wall has only one component, the body modifier applies to the entire wall. If the wall has multiple components, the modifier applies only to the component that you specify.
If you add the body modifier to a wall component, or use a body modifier to replace the component, the body modifier uses the material assignment and display properties of the wall component.
After you create a body modifier from an object, you can delete the original object. However, if you have created a complex object, such as a mass group comprising many mass elements, you may want to retain the object in the drawing until you are sure you have the results you want for the wall.