sin vertex displacement shader

 The following vertex-surface shader moves vertices up and down based on some sine waves and the time variable. Combining lots of waves is a cool way to generate funky displacements.

Things to note - we calculate a new normal in the vert function to prevent weird shading issues.

 Shader "Dave/Unlit/waves"
{
    Properties
    {
        _MainTex ("Texture", 2D) = "white" {}
        _Tint("Colour Tint",color)=(1,1,1,1)
        _Freq("Frequency",Range(0,5))=3
        _Speed("Speed",Range(0,100))=10
        _Amp("Amplitude",Range(0,1))=0.5
    }
    SubShader
    {
       CGPROGRAM
    #pragma surface surf Lambert vertex:vert
       struct Input {
            float2 uv_MainTex;
            float3 vertColor;
};
        float4 _Tint;
        float _Freq;
        float _Speed;
        float _Amp;

        struct appdata {
            float4 vertex :POSITION;
            float3 normal : NORMAL;
            float4 texcoord:TEXCOORD0;
            float4 texcoord1:TEXCOORD1;

        };

        void vert(inout appdata v, out Input o) {
            UNITY_INITIALIZE_OUTPUT(Input, o);
            float t = _Time * _Speed;
            float waveHeight = sin(t + v.vertex.x*_Freq)*_Amp+
                sin(t*2+v.vertex.x*_Freq*2);
            v.vertex.y = v.vertex.y + waveHeight;
            v.normal = normalize(float3(v.normal.x + waveHeight, v.normal.y, v.normal.z));
            o.vertColor = waveHeight + 2;
        }

        sampler2D _MainTex;
        void surf(Input IN, inout SurfaceOutput o) {
            float4 c = tex2D(_MainTex, IN.uv_MainTex);
            o.Albedo = c * IN.vertColor.rgb;

        }

       ENDCG
    }
            Fallback "Diffuse"
}