Untiy shader 初学 淡入淡出效果

    Properties
	{
		_MainTex ("Texture", 2D) = "white" {}
		_Range("Range",Range(0,1))=0
		_FadeRange("FadeRange",Range(3,100))=3
	}
	SubShader
	{
		Tags { "RenderType"="Opaque" }
		Blend srcAlpha OneMinusSrcAlpha

		LOD 100

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

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

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

			};

			sampler2D _MainTex;
			float4 _MainTex_ST;
			
			float _Range;
			float _FadeRange;
			
			v2f vert (appdata v)
			{
				v2f o;
				o.vertex = UnityObjectToClipPos(v.vertex);
				o.uv = TRANSFORM_TEX(v.texcoord, _MainTex);

				return o;
			}
			
			fixed4 frag (v2f i) : SV_Target
			{
				
				fixed4 col = tex2D(_MainTex, i.uv-1);
				
				float x=i.uv.y;

				if(_Range<1)
					x=smoothstep(abs(1-_Range),1,x);
				else
					x=1;

				fixed3 target=col;
				
				return fixed4(target,_FadeRange*x);
			}
			ENDCG
		}
	}