ScriptReference/MonoBehaviour.FixedUpdate

[giscus[bot]]

ScriptReference/MonoBehaviour.FixedUpdate

https://docs.unity3d.com/ScriptReference/MonoBehaviour.FixedUpdate.html

[vertxxyz]

Do not poll instantaneous input functions in FixedUpdate. It doesn't run in sync with Update or LateUpdate, so polling functions like GetKeyDown will inconsistently register.
Instead store the state as polled from Update and consume it here as necessary.

[vertxxyz]

See Important Classes - Time's Fixed Timestep for another detailed writeup with diagrams and graphs on how fixed update works.

[akela-morse]

FixedUpdate runs prior to the internal physics update so that you can have a chance to change the properties of Rigidbody and other Physics components before they get written to Transform.

But there are specific cases where you may want to run some code after the physics update. You can fake a “LateFixedUpdate” by writing FixedUpdate as an asynchronous Awaitable and await for FixedUpdateAsync. This will effectively run the code after the internal physics update and after animations are evaluated (provided the Animator has been set to update on the fixed loop).

Be aware that this trick, while useful in some very specific cases (such as handling moving platforms on the fixed loop), can potentially cause some serious issues if you try to query the physics engine at this time. Double-check the full list of internal functions on the execution order to make sure you're not doing anything wrong. Always update your Rigidbody components in the normal FixedUpdate loop.