# gravity The gravity for the simulation relative to the simulation entity. ``` var gravity: SIMD3 ``` ## Discussion The value stored in this property is the gravitational acceleration applied to dynamic physics body entities every frame along the negative world y-axis. The default value is `-9.81` meters per second squared. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)