【着色器实现Swaying摇曳效果_Shader效果第四篇】

Shader "Swaying"
{
    Properties
    {
        _MainTex ("Main Texture", 2D) = "white" {}
    _Color("Main Color", Color) = (1,1,1,1)
    _Alpha("General Alpha",  Range(0,1)) = 1

    _GrassSpeed("Speed", Range(0,50)) = 2
    _GrassWind("Bend amount", Range(0,50)) = 20

    _WaveAmount("Wave Amount", Range(0, 25)) = 7
    _WaveSpeed("Wave Speed", Range(0, 25)) = 10
    _WaveStrength("Wave Strength", Range(0, 25)) = 7.5
    _WaveX("Wave X Axis", Range(0, 1)) = 0
    _WaveY("Wave Y Axis", Range(0, 1)) = 0.5

    _ClipUvLeft("Clipping Left", Range(0, 1)) = 0
    _ClipUvRight("Clipping Right", Range(0, 1)) = 0
    _ClipUvUp("Clipping Up", Range(0, 1)) = 0
    _ClipUvDown("Clipping Down", Range(0, 1)) = 0
    }

    SubShader
    {
        Tags {"Queue" = "Transparent" "RenderType"="Opaque" "IgnoreProjector" = "True" }        
        Blend SrcAlpha OneMinusSrcAlpha
        ZWrite Off
        Cull Off

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "UnityCG.cginc"
            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
        half4 color : COLOR;
            };

            struct v2f
            {
                float2 uv : TEXCOORD0;
                float4 vertex : SV_POSITION;
        half4 color : COLOR;
            };

            sampler2D _MainTex;
            half4 _MainTex_ST, _MainTex_TexelSize, _Color;
      half _Alpha;
            float _RandomSeed;

      half _GrassSpeed, _GrassWind, _GrassRadialBend;
      float _WaveAmount, _WaveSpeed, _WaveStrength, _WaveX, _WaveY;
      half _ClipUvLeft, _ClipUvRight, _ClipUvUp, _ClipUvDown;

            v2f vert (appdata v)
            {
                v2f o;
        o.vertex = UnityObjectToClipPos(v.vertex);
                o.uv = TRANSFORM_TEX(v.uv, _MainTex);
        o.color = v.color;
                return o;
            }

            half4 frag (v2f i) : SV_Target
            {
        float2 uvRect = i.uv;
        half2 center = half2(0.5, 0.5);

        half windOffset = sin((_Time + _RandomSeed) * _GrassSpeed * 10);
        half2 windCenter = half2(0.5, 0.1);
        i.uv.x = fmod(abs(lerp(i.uv.x, i.uv.x + (_GrassWind * 0.01 * windOffset), uvRect.y)), 1);
        half2 delta = i.uv - windCenter;
        half delta2 = dot(delta.xy, delta.xy);
        half2 delta_offset = delta2 * windOffset;
        i.uv = i.uv + half2(delta.y, -delta.x) * delta_offset * _GrassRadialBend;

        float2 uvWave = half2(_WaveX *  _MainTex_ST.x, _WaveY *  _MainTex_ST.y) - i.uv;
              uvWave %= 1;
        uvWave.x *= _ScreenParams.x / _ScreenParams.y;
              float waveTime = _Time.y + _RandomSeed;
        float angWave = (sqrt(dot(uvWave, uvWave)) * _WaveAmount) - ((waveTime *  _WaveSpeed));
        i.uv = i.uv + uvWave * sin(angWave) * (_WaveStrength / 1000.0);

        half2 tiledUv = half2(i.uv.x / _MainTex_ST.x, i.uv.y / _MainTex_ST.y);
        clip((1 - _ClipUvUp) - tiledUv.y);
        clip(tiledUv.y - _ClipUvDown);
        clip((1 - _ClipUvRight) - tiledUv.x);
        clip(tiledUv.x - _ClipUvLeft);

        half4 col = tex2D(_MainTex, i.uv) * i.color;
        half originalAlpha = col.a;


        col.a *= _Alpha;
        col *= _Color;
                return col;
            }
            ENDCG
        }
    }
  Fallback "Sprites/Default"
}