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
｝
｝
｝