설명

This function is called every fixed framerate frame, if the MonoBehaviour is enabled.

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); } }