This page is not available in the language you have chosen. It will be displayed in English by default. If you would like to view it in a different language, you can try selecting another language.
Given the ever increasing complexity of 3D meshes, proxy shapes must be used to drive physics simulations in real time 3D rendering applications; Physics Bodies (BodyInstances) are the simplified 3D meshes that Unreal Engine 4 uses for physics simulations. They can be formed of boxes, spheres, capsules, or convex hulls.
The following links have information on Physics Bodies.