Unity Shader（九）压缩和混合纹理贴图_unity地形材质混合效果

效果说明示例： 

 使用纹理贴图示例：

混合系数贴图示例：

Shader "Custom/BasicDiffuse"
{
	//属性
	Properties
	{
		_MainTint("Diffuse Tint",Color)=(1,1,1,1)
		_ColorA("Terrain Color A",Color)=(1,1,1,1)
		_ColorB("Terrain Color B",Color)=(1,1,1,1)
		_RTexture("Red Channel Texture",2D) = ""{}
		_GTexture("Green Channel Texture",2D) = ""{}
		_BTexture("Blue Channel Texture",2D) = ""{}
		_ATexture("Alpha Channel Texture",2D) = ""{}
		_BlendTex("Blend Texture",2D) = ""{}
	}
 
	SubShader
	{
		//渲染类型为不透明物体
		Tags{"RenderType" = "Opaque"}
 
		//层级细节
		LOD 200
 
		CGPROGRAM
 
		//编译指令，定义表面着色器和将要使用的光照模型Lambert(漫反射)
		#pragma surface surf Lambert
 
		//声明属性关联		
		float4 _MainTint;
		float4 _ColorA;
		float4 _ColorB;
		sampler2D _RTexture;
		sampler2D _GTexture;
		sampler2D _BTexture;
		sampler2D _ATexture;
		sampler2D _BlendTex;
 
		//表面着色器输入结构体
		struct Input
		{
			//纹理的UV坐标值
			float2 uv_RTexture;
			float2 uv_GTexture;
			float2 uv_BTexture;
			float2 uv_ATexture;
			float2 uv_BlendTex;
		};
 
		//表面着色器
		void surf(Input IN, inout SurfaceOutput o)
		{
			float4 blendData = tex2D(_BlendTex, IN.uv_BlendTex);
			float4 rTexData = tex2D(_RTexture, IN.uv_BlendTex);
			float4 gTexData = tex2D(_GTexture, IN.uv_BlendTex);
			float4 bTexData = tex2D(_BTexture, IN.uv_BlendTex);
			float4 aTexData = tex2D(_ATexture, IN.uv_BlendTex);
 
			//使用线性插值对纹理进行混合
			float4 finalColor;
			finalColor = lerp(rTexData, gTexData, blendData.g);
			finalColor = lerp(finalColor, bTexData, blendData.g);
			finalColor = lerp(finalColor, aTexData, blendData.g);
			finalColor.a = 1.0;
 
			//将混合纹理与色调值相乘，并使用红色通道来确定两个不同地形将形成怎样的色调
			float4 terrainLayers = lerp(_ColorA, _ColorB, blendData.r);
			finalColor *= terrainLayers;
			finalColor = saturate(finalColor);
 
			o.Albedo = finalColor.rgb * _MainTint.rgb;
			o.Alpha = finalColor.a;
		}
		ENDCG
	}
		FallBack "Diffuse"
}

材质球设置

效果图：

lerp()函数

lerp(a,b,f) ---功能描述--->(1-f)*a+b*f

效果示例：