MonoBehaviour.FixedUpdate 固定更新

function FixedUpdate () : void

Description描述

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

当MonoBehaviour启用时，其 FixedUpdate 在每一帧被调用。

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.

处理Rigidbody时，需要用FixedUpdate代替Update。例如:给刚体加一个作用力时，你必须应用作用力在FixedUpdate里的固定帧，而不是Update中的帧。(两者帧长不同)

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
	void FixedUpdate() {
		rigidbody.AddForce(Vector3.up);
	}
}

// Apply a upwards force to the rigid body every frame
// 每帧应用一个向上的力到刚体上
function FixedUpdate () {
	rigidbody.AddForce ( Vector3.up );
}

In order to get the elapsed time since last call to FixedUpdate, use Time.deltaTime This function is only called if the Behaviour is enabled. Override this function in order to provide your component's functionality.

为了获取自最后一次调用FixedUpdate所用的时间，可以用Time.deltaTime。这个函数只有在Behaviour启用时被调用。实现组件功能时重载这个函数。