Unity Shader UV平移、旋转、缩放效果

平移、旋转、缩放、扭曲这几个效果在很多游戏场景中都会运用到，本篇文章就给大家分享下在Unity中基于Shader实现UV平移、旋转、缩放效果。

平移效果：

旋转：

缩放：

扭曲效果：

shader代码：

Shader "Custom/MoveUV"
｛
    Properties
    ｛
        _MainTex ("Texture", 2D) = "white" ｛｝
        _Speed("Rotate Speed",Range(0,4))=1
    ｝
    SubShader
    ｛
        Tags ｛ "RenderType"="Opaque" ｝
        LOD 100
        Pass
        ｛
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag           
            #include "UnityCG.cginc"
            sampler2D _MainTex;
            float _Speed;
            struct a2v｛
                float4 vertex:POSITION;
                float4 texcoord:TEXCOORD;
            ｝;
            struct v2f｛
                float4 pos:POSITION;
                float4 uv:texcoord;
            ｝;
            v2f vert(a2v v)｛
                v2f o;
                o.pos=UnityObjectToClipPos(v.vertex);
                o.uv=v.texcoord;
                return o;
            ｝
            fixed4 frag(v2f i):SV_Target｛
                //扭曲效果
                fixed2 uv = i.uv - fixed2(0.5,0.5);
                float angle = _Speed * 0.1745/(length(uv) + 0.1);//加0.1是放置length（uv）为0
                float angle2 = angle * _Time.y;
                uv = float2(uv.x*cos(angle2)-uv.y*sin(angle2),uv.y*cos(angle2)+uv.x*sin(angle2));
                uv+=fixed2(0.5,0.5);
                fixed4 c = tex2D(_MainTex,uv);
                return c;
                //缩放
                //float4 uv = i.uv;
                //uv.x*=_Speed;
                //uv.w=0.5;
                //return tex2D(_MainTex,uv);
                //旋转
                //float2 uv=i.uv.xy-float2(0.5,0.5);
                //uv=float2(uv.x*cos(_Speed*_Time.y)-uv.y*sin(_Speed*_Time.y),uv.y*cos(_Speed*_Time.y) + uv.x*sin(_Speed*_Time.y));
                //uv+=float2(0.5,0.5);
                //fixed4 lateUV = tex2D(_MainTex,uv);
                //return lateUV;
                //平移
                //return tex2D(_MainTex,i.uv - _Time.x*fixed2(2,0)* _Speed);
            ｝
            ENDCG
        ｝
    ｝
｝