Unity2D horizontal version game tutorial 4 - item collection and physical materials

Let's expand the background a bit first,ctrl+DDuplicate a background image and adjust the position,Expand the map a little bit

 然后再HierarchyThe interface creates an empty component named Collection,表示物品,Create an empty child component called Cherries,This is the cherry item,Pickable,The property bar on the right givesCherries添加一个Sprite Renderer(精灵渲染器)

 Next we will giveCherriesModel is set up,我们到Item文件夹,There are three different items here,The third folder is some fruit,We choose cherries,Don't forget to change the pixel of the cherry to 32

 Then we drag the animation for the first frame toCherries的Sprite Renderer

 Set the layer order,Set to what we have set beforeCollection图层,This way you can see the item in the scene

 Then we add an animation effect to the item,Same as the previous character animation,这里就略过了,If you forget, you can read the previous article,After the animation is done,我们还需要给Cherries添加碰撞体,property bar thereCherries添加一个circle Collider 2D

 调整一下位置,然后勾选Is Trigger,Think of this collider as a trigger

 Then we're going to write a little bit of code

First create a variable that counts,Used to count the character's score or the number of items collected

 There is also the variable that the character hits the item to destroy the item and counts it1

We treat this cherry as oneTrigger（触发器）,所以我们用Triggertype to determine whether it is a collectible item,这里TriggerThe type of item is set by settingTag来区分

 新建一个Tag,命名为Collection

 Then we will cherryTag改成Collection,Behind the different types of collectible itemsTag都改成Collection

 设置完TagThen we can write it in the code

 这里输出cherries的值来debug,我们回到unity运行,It prints when we hit a cherrycherries的值是1

 Don't forget to take usdebugComment out that line of code

We've only put a cherry on the map right now,If we want to put more cherries we have to put them one by one,And if you want to make changes to all the cherries, you need to set them one by one,Here we introduce prefabs（Perfabs）的概念,The role of prefabs is to reuse resources.Objects that are reused in the scene are made into prefabs as much as possible.

我们通过将HierarchyDrag the object in the opposite direction into the folder to make the object into a prefab,Then drag the prefab in the folder to the scene to become a prefab instance.We modify the prefab,All prefab instances are modified accordingly,We modify the prefab instance,Other examples of prefabs including prefabs do not change.

So once we have a prefab, we can keep duplicating it,Modify the prefab when you want to change it. All prefab instances are changed accordingly,If you want to have a deeper understanding of prefabs, you can refer to this article详解Unity中的预制体_Dream Xiaotianyou's blog-CSDN博客_unity预制体

然后我们创建一个文件夹,命名为Prefabs,然后将Hierarchy里面的cherries拖进Prefabs文件夹,这样就有了cherries预制体,这时候cherries会变成蓝色.

 然后我们ctrl+D复制一下cherries,Add a little more cherry to the map

 This completes the collection of items,Now let's modify the character to be stuck on other collidersbug.The character itself has a collider,tilemapThere is also a collider,So when the character touches other objects it will get stuck on the object,Because of friction,We add a smooth physical material to the character

我们在Assets文件夹右键->Create->2D->physics Material 2D,创建一个2D的物理材质

 Then adjust both parameters of this material to 0,friction是摩擦力,bouncinessis the resilience

 Then drag this material to the charactercircle collider 2D

 This way our character doesn't rub against other colliders

Finally, paste the complete code

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

public class playercontroller : MonoBehaviour
{
    private Rigidbody2D rb;//获得Rigidbody2D组件
    private Collider2D coll;//获得Collider2D组件
    private Animator anim;//获得动画组件
    public float speed, jumpForce;//公开,设置速度和跳跃力
    public LayerMask ground;//获得地面图层
    public Transform groundCheck;//Detects if the character hits the ground
    private bool isJump, isGround;//判断是否按下空格键,判断是否在地面
    private int jumpCount;//Used to set the character is a few jumps
    private int cherries;//计数变量
    //初始化
    void Start()
    {
        rb = GetComponent<Rigidbody2D>();
        coll = GetComponent<Collider2D>();
        anim = GetComponent<Animator>();
    }
    void Update()
    {
        //如果按下空格键并且在地面上
        if (Input.GetKeyDown(KeyCode.Space) && jumpCount > 0)
        {
            isJump = true;
        }
    }
    private void FixedUpdate()
    {
        isGround = Physics2D.OverlapCircle(groundCheck.position, 0.1f, ground);
        Movement();
        Jump();
        SwitchAnim();
    }
    //基础移动
    void Movement()
    {
        float horizontal = Input.GetAxisRaw("Horizontal");
        rb.velocity = new Vector2(horizontal * speed, rb.velocity.y);//设置x轴的移动
        //设置角色的转向问题
        if (horizontal != 0)
        {
            transform.localScale = new Vector3(horizontal, 1, 1);
            anim.SetBool("run", true);
        }
        else
            anim.SetBool("run", false);
    }
    //跳跃
    void Jump()
    {
        //If you set a double jump on the ground
        if (isGround)
        {
            jumpCount = 2;
        }
        //Press the jump key and be on the ground
        if (isJump && isGround)
        {
            rb.velocity = new Vector2(rb.velocity.x, jumpForce);
            jumpCount--;
            isJump = false;
        }
        //Press the jump key without being on the ground andjumpCount大于0
        else if (isJump && !isGround && jumpCount > 0)
        {
            rb.velocity = new Vector2(rb.velocity.x, jumpForce);
            jumpCount--;
            isJump = false;
        }
    }
    //切换动画
    void SwitchAnim()
    {
        //if in a falling state
        if (rb.velocity.y < 0 && !isGround)
        {
            anim.SetBool("fall", true);
            anim.SetBool("jump", false);
        }
        //如果在跳跃状态
        if (!isGround && rb.velocity.y > 0)
        {
            anim.SetBool("jump", true);
        }
        //如果在地面上
        else if (coll.IsTouchingLayers(ground))
        {
            anim.SetBool("fall", false);
        }
    }
    //Determine if the object is touched
    private void OnTriggerEnter2D(Collider2D collision)
    {
        if(collision.tag=="Collection")
        {
            Destroy(collision.gameObject);
            cherries++;
            //Debug.Log(cherries);
        }
    }
}