Unity教程之-愤怒的小鸟飞行弹道

 

本节Unity3d教程我们来学习下愤怒的小鸟飞行弹道制作原理,抛体运动的类型:
“很多子弹不仅垂直运动而且追随着水平的运动。那就,当他们向上移动或向下运动时也正在水平方向移动。弹体的运动 — — 横向和纵向

运动的两个组成部分。
垂直运动:
在垂直运动,重力作用在物体上,并给予负加速度”-9.8 m/s²”(重心加速度)。这意味着物体的速度在每一秒减小-9.8 米/² 。自由落体的速度是 V = g * t。 如果我们有初始速度那么,物体下落速度方程: V = Vi + g * t 加速度是-9.8 m/s²,在做自由落体时距离的计算方程 ;S= 1/2 * g * t * t ;考虑对象的初始速度情况下的

公式计算 ;S = Vi * t – 1/2 * g * t * t ;距离被减去,因为 g 的方向是向下。
横向运动:
在水平运动,没有外力作用在水平方向匀速运动。因而在此基础上,是恒定的速度的 X 分量,在 X 方向的加速度为零。下面给出了用于计算距离和速度方程。S = v * t ; 下面是简单的 c# 代码,将显示球的弹道路径时它会沿着路径抛出。
注: 添加如下脚本到枪炮对象上。 创建 prefebs 球和轨迹点将运行时实例化。 球必须有Collider和Rigidbody。
截图:

       


using UnityEngine;
using System.Collections;
using System.Collections.Generic;

public class CannonScript : MonoBehaviour
{
// TrajectoryPoint and Ball will be instantiated
public GameObject TrajectoryPointPrefeb;
public GameObject BallPrefb;

private GameObject ball;
private bool isPressed, isBallThrown;
private float power = 25;
private int numOfTrajectoryPoints = 30;
private List trajectoryPoints;
//---------------------------------------
void Start ()
{
trajectoryPoints = new List();
isPressed = isBallThrown =false;
//   TrajectoryPoints are instatiated
for(int i=0;i<numOfTrajectoryPoints;i++)
{
GameObject dot= (GameObject) Instantiate(TrajectoryPointPrefeb);
dot.renderer.enabled = false;
trajectoryPoints.Insert(i,dot);
}
}
//---------------------------------------
void Update ()
{
if(isBallThrown)
return;
if(Input.GetMouseButtonDown(0))
{
isPressed = true;
if(!ball)
createBall();
}
else if(Input.GetMouseButtonUp(0))
{
isPressed = false;
if(!isBallThrown)
{
throwBall();
}
}
// when mouse button is pressed, cannon is rotated as per mouse movement and projectile trajectory path is displayed.
if(isPressed)
{
Vector3 vel = GetForceFrom(ball.transform.position,Camera.main.ScreenToWorldPoint(Input.mousePosition));
float angle = Mathf.Atan2(vel.y,vel.x)* Mathf.Rad2Deg;
transform.eulerAngles = new Vector3(0,0,angle);
setTrajectoryPoints(transform.position, vel/ball.rigidbody.mass);
}
}
//---------------------------------------
// Following method creates new ball
//---------------------------------------
private void createBall()
{
ball = (GameObject) Instantiate(BallPrefb);
Vector3 pos = transform.position;
pos.z=1;
ball.transform.position = pos;
ball.SetActive(false);
}
//---------------------------------------
// Following method gives force to the ball
//---------------------------------------
private void throwBall()
{
ball.SetActive(true);
ball.rigidbody.useGravity = true;
ball.rigidbody.AddForce(GetForceFrom(ball.transform.position,Camera.main.ScreenToWorldPoint(Input.mousePosition)),ForceMode.Impulse);
isBallThrown = true;
}
//---------------------------------------
// Following method returns force by calculating distance between given two points
//---------------------------------------
private Vector2 GetForceFrom(Vector3 fromPos, Vector3 toPos)
{
return (new Vector2(toPos.x, toPos.y) - new Vector2(fromPos.x, fromPos.y))*power;
}
//---------------------------------------
// Following method displays projectile trajectory path. It takes two arguments, start position of object(ball) and initial velocity of object(ball).
//---------------------------------------
void setTrajectoryPoints(Vector3 pStartPosition , Vector3 pVelocity )
{
float velocity = Mathf.Sqrt((pVelocity.x * pVelocity.x) + (pVelocity.y * pVelocity.y));
float angle = Mathf.Rad2Deg*(Mathf.Atan2(pVelocity.y , pVelocity.x));
float fTime = 0;

fTime += 0.1f;
for (int i = 0 ; i < numOfTrajectoryPoints ; i++)
{
float dx = velocity * fTime * Mathf.Cos(angle * Mathf.Deg2Rad);
float dy = velocity * fTime * Mathf.Sin(angle * Mathf.Deg2Rad) - (Physics2D.gravity.magnitude * fTime * fTime / 2.0f);
Vector3 pos = new Vector3(pStartPosition.x + dx , pStartPosition.y + dy ,2);
trajectoryPoints[i].transform.position = pos;
trajectoryPoints[i].renderer.enabled = true;
trajectoryPoints[i].transform.eulerAngles = new Vector3(0,0,Mathf.Atan2(pVelocity.y - (Physics.gravity.magnitude)*fTime,pVelocity.x)*Mathf.Rad2Deg);
fTime += 0.1f;
}
}
}

好了本篇unity3d教程到此结束!