【Unity】指定の高さ（ワールド座標）以降は描画しないシェーダー

HeightDisappear.shader

Shader "Custom/HeightDisappear" {
	Properties {
		_Color ("Color", Color) = (1,1,1,1)
		_MainTex ("Albedo (RGB)", 2D) = "white" {}
		_Height ("Height", Float) = 0.0
		_Glossiness ("Smoothness", Range(0,1)) = 0.5
		_Metallic ("Metallic", Range(0,1)) = 0.0
	}
	SubShader {
		Tags { "RenderType"="Opaque" }
		LOD 200

		CGPROGRAM
		#pragma surface surf Standard fullforwardshadows
		#pragma target 3.0

		sampler2D _MainTex;
        	half _Glossiness;
        	half _Metallic;
        	fixed4 _Color;
        	fixed _Height;
        
		struct Input {
			float2 uv_MainTex;
       			float3 worldPos;
		};
        		      		
		void surf (Input IN, inout SurfaceOutputStandard o) {		
			fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
			if(IN.worldPos.y<_Height) discard;
            
            		o.Albedo = c.rgb;
			o.Metallic = _Metallic;
			o.Smoothness = _Glossiness;
			o.Alpha = c.a;
		}
		ENDCG
	}
	FallBack "Diffuse"
}