Shader "Custom/Test"
{
    Properties
    {
        _MainTex ("Albedo Texture", 2D) = "white" {}
        _TintColor("Tint Color", Color) = (1,1,1,1)
        _Transparency("Transparency", Range(0.0,1)) = 1
        _Height("Height", Range(0,100)) = 1
    }

    SubShader
    {
        Tags {"Queue"="Transparent" "RenderType"="Transparent" }
        LOD 100

        ZWrite Off
        Blend SrcAlpha OneMinusSrcAlpha

        Pass
        {
            CGPROGRAM
            #pragma vertex vert
            #pragma fragment frag

            #include "UnityCG.cginc"

            struct appdata
            {
                float4 vertex : POSITION;
                float2 uv : TEXCOORD0;
            };

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

            sampler2D _MainTex;
            float4 _MainTex_ST;
            float4 _TintColor;
            float _Transparency;
            float _Height;

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

            fixed4 frag (v2f i) : SV_Target {
                fixed4 col = tex2D(_MainTex, i.uv) * _TintColor;

                if(i.vertex.y<_Height){
                    float y = i.vertex.y;
                    col.a = 1-_Transparency*(_Height-y);
                }

                return col;
            }
            ENDCG
        }
    }
}