草摆动shader

Shader "Custom/Grass" {
    Properties {
        _MainTex ("Grass Texture", 2D) = "white" {}
        _TimeScale ("Time Scale", float) = 0.2
    }  

    SubShader{
        Tags{"Queue"="Transparent" "RenderType"="Opaque" "IgnoreProject"="True"}
        Pass{
            Tags{"LightMode"="ForwardBase"}  

            ZWrite Off
            Blend SrcAlpha OneMinusSrcAlpha
            Cull Off  

            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag
            #include "UnityCG.cginc"   

            sampler2D _MainTex;
            half _TimeScale;  

            struct a2v {
                float4 vertex : POSITION;
                float4 texcoord : TEXCOORD0;
            };  

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

            v2f vert(a2v v){
                v2f o;
                float4 offset = float4(,,,);
                offset.z = sin(3.1415 * _Time.y * clamp(v.texcoord.y-0.5, , ))  * _TimeScale;
                o.pos = UnityObjectToClipPos(v.vertex + offset);
                o.uv = v.texcoord.xy;
                return o;
            }  

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

            ENDCG
        }
    }
    FallBack Off
} 

效果: