MonoBehaviour.FixedUpdate()

Description

Эта функция вызывается с частотой фиксированных кадров (fixed framerate), если MonoBehaviour включен.

FixedUpdate should be used instead of Update when dealing with Rigidbody. For example when adding a force to a rigidbody, you have to apply the force every fixed frame inside FixedUpdate instead of every frame inside Update.

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour
{
    public Rigidbody rb;

    void Start()
    {
        rb = GetComponent<Rigidbody>();
    }

    void FixedUpdate()
    {
        rb.AddForce(10.0f * Vector3.up);
    }
}