三、效果实现：11、翻书效果

shader

Shader "Learn Unity Shader/openBook"
{
    Properties
    {
        //正面纹理
        _MainTex("Texture", 2D) = "white" {}
        //背面纹理
        _SecTex("SecTex",2D) = "White"{}

        //旋转角度
        _Angle("Angle",Range(-180,0)) = 0
        //波长
        _WaveLength("WaveLength",Range(-1,1)) = 0

    }
        SubShader
 {

   Pass
   {
         //剔除背面
     Cull Back

         CGPROGRAM
         #pragma vertex vert
         #pragma fragment frag

         #include "UnityCG.cginc"

         struct appdata
         {
           float4 vertex : POSITION;
           float2 uv : TEXCOORD0;
         };

         struct v2f
         {
           float2 uv : TEXCOORD0;
           float4 vertex : SV_POSITION;
         };

         sampler2D _MainTex;
     float4 _MainTex_ST;
     //角度
     float _Angle;
     //波长
     float _WaveLength;

     v2f vert(appdata v)
     {
       v2f o;
       //旋转之前向右偏移5个单位
       v.vertex -= float4(5,0,0,0);
       float s;
       float c;
       //通过该方法可以计算出该角度的正余弦值
       sincos(radians(_Angle),s,c);
       //旋转矩阵
       float4x4 rotateMatrix = {
         c ,s,0,0,
         -s,c,0,0,
         0 ,0,1,0,
         0 ,0,0,1
       };
       //根据x坐标，通过正弦函数计算出 y坐标的正弦值， _WaveLength 控制波长， 振幅就跟随角度正弦值动态变化
       v.vertex.y = sin(v.vertex.x * _WaveLength) * s;

       //顶点左乘以旋转矩阵
       v.vertex = mul(rotateMatrix,v.vertex);
       //旋转之后偏移回来
       v.vertex += float4(5,0,0,0);

       //模型空间转换到裁剪空间
       o.vertex = UnityObjectToClipPos(v.vertex);
       o.uv = v.uv;
       return o;
     }


     fixed4 frag(v2f i) : SV_Target
     {
       fixed4 col = tex2D(_MainTex, i.uv);
       return col;
     }
     ENDCG
   }

    Pass
   {
         //剔除正面
     Cull Front

         CGPROGRAM
         #pragma vertex vert
         #pragma fragment frag

         #include "UnityCG.cginc"

         struct appdata
         {
           float4 vertex : POSITION;
           float2 uv : TEXCOORD0;
         };

         struct v2f
         {
           float2 uv : TEXCOORD0;
           float4 vertex : SV_POSITION;
         };

         //角度
         float _Angle;
         //波长
         float _WaveLength;

         sampler2D _SecTex;
     float4 _SecTex_ST;

         v2f vert(appdata v)
         {
           v2f o;
           //旋转之前向右偏移5个单位
           v.vertex -= float4(5,0,0,0);
           float s;
           float c;
           //通过该方法可以计算出该角度的正余弦值
           sincos(radians(_Angle),s,c);
           //旋转矩阵
           float4x4 rotateMatrix = {
             c ,s,0,0,
             -s,c,0,0,
             0 ,0,1,0,
             0 ,0,0,1
           };
           //根据x坐标，通过正弦函数计算出 y坐标的正弦值， _WaveLength 控制波长， 振幅就跟随角度正弦值动态变化
           v.vertex.y = sin(v.vertex.x * _WaveLength) * s;

           //顶点左乘以旋转矩阵
           v.vertex = mul(rotateMatrix,v.vertex);
           //旋转之后偏移回来
           v.vertex += float4(5,0,0,0);

           //模型空间转换到裁剪空间
           o.vertex = UnityObjectToClipPos(v.vertex);
           o.uv = v.uv;
           return o;
         }


         fixed4 frag(v2f i) : SV_Target
         {
           fixed4 col = tex2D(_SecTex, i.uv);
           return col;
         }
         ENDCG
       }
 }
}

控制脚本

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

public class BookCtrl : MonoBehaviour
{
    private static int s_Angle = -1;
    public float playTime = 1;
    Material mMat = null;
    private float tempAngleValue = -180;
    void Awake()
    {
        mMat = this.GetComponent<MeshRenderer>().material;
        s_Angle = Shader.PropertyToID("_Angle");
    }

    public void DisPlay()
    {
        StartCoroutine(DisplayBook());
    }

    private IEnumerator DisplayBook()
    {
        yield return null;
        tempAngleValue = -180;
        playTime = 1;
        float rate = (float)180 / (float)((float)playTime/Time.deltaTime);//公式：(playTime / Time.deltaTime) * rate = 180
        do
        {
            playTime -= Time.deltaTime;
            tempAngleValue += rate;
            if (tempAngleValue > 0)
            {
                break;
            }
            mMat.SetFloat(s_Angle, tempAngleValue);
            yield return new WaitForSeconds(Time.deltaTime);
        } while (playTime > 0);
    }

    private void Update()
    {
        if (Input.GetKeyDown(KeyCode.Space))
        {
            DisPlay();
        }
    }
}

面板参数及效果

11.gif

• 新建Plane，拖翻书材质给它

  
  book.png