Unity3d《Shader篇》地球旋转上空悬浮云层

记得把纹理设置成Repeat

Shader "Custom/Earth" {
	Properties {
		_MainTex ("Base (RGB)", 2D) = "white" {}
		_CloudTex ("Base (RGB)", 2D) = "white" {}
	}
	SubShader {

		Pass{
		Tags { "RenderType"="Opaque" }
		LOD 200

		CGPROGRAM
		#pragma vertex vert
		#pragma fragment frag

		#include "UnityCG.cginc"

		sampler2D _MainTex;
		sampler2D _CloudTex;
		float4 _MainTex_ST;
		struct Input {
			float4 pos : SV_POSITION;
			float2 uv;
		};

		Input vert(appdata_base v)
		{
			Input output;
			output.pos = mul(UNITY_MATRIX_MVP,v.vertex);
			output.uv =  TRANSFORM_TEX (v.texcoord, _MainTex);

			return output;
		}

		half4 frag (Input i):COLOR
		{
			float2 uv = i.uv;
			uv.x=i.uv.x + -_Time*0.3;
			half4 col = tex2D(_MainTex,uv);

			float2 uv_cloud = i.uv;
			uv_cloud.x=i.uv.x+ -_Time*0.8;

			half4 tex_clouddDepth = tex2D(_CloudTex,uv_cloud);

			half4 col_cloud = float4(1,1,1,0)*(tex_clouddDepth.x);

			return lerp(col,col_cloud,0.5f);

		}
		ENDCG
		}
	}
	FallBack "Diffuse"
}