The mass of the body, in kilograms.
- iOS 8.0+
- macOS 10.10+
- Mac Catalyst 13.0+
- tvOS 9.0+
- watchOS 3.0+
The mass of a body affects its momentum and how it responds to forces. The default mass for dynamic bodies is
1. The default mass for static and kinematic bodies is
0, but these bodies are unaffected by mass.
Note that you need not use realistic measurements for the bodies in your app—the effects of the physics simulation depend on the relative masses of different bodies, not the absolute values. You may use whatever values produce the behavior or gameplay you’re looking for as long as you use them consistently.