shader学习(一)

1、固定功能着色器（Fixed Function Shader）

Shader "shader/eff"
{
	Properties
	{
		_Color("Main Color", Color) = (1,1,1,1)
		_Ambient("Ambient",Color) = (0.3,0.3,0.3,0.2)
		_Specular("Sp",Color) = (1,1,1,1)
		_Shininess("Shininess",range(0,8)) = 4
		_Emission("Emis",Color)=(1,1,1,1)
		_MainTex("MainTex",2d)=""{}
		_MainTex2("MainTex2",2d) = ""{}
		_Constant("ConstantColor",Color)=(1,1,1,0.3)

	}
		SubShader
	{
			Tags{"Queue"="Transparent"} //渲染通道选择透明
		   pass {
			Blend SrcAlpha OneMinusSrcAlpha //透明混合
		/*color(1,1,0,1)*/
		   color[_Color]
		   material{
				diffuse[_Color] //设置漫反射颜色
				ambient[_Ambient] //环境光
				specular[_Specular] //高光反射
			   shininess[_Shininess]//高光反射的区域
			   emission[_Emission]//自发光
			}
			lighting on //启用光照
			separatespecular on //启用独立镜面的高光
			settexture[_MainTex] //设置纹理贴图
			{
			   combine texture * primary double //贴图设置之前的预设
				//combine texture* primary quad //贴图设置之前的预设
			}
				settexture[_MainTex2] //设置第二张纹理贴图 
			{
			 //  combine texture * previous double,texture //此贴图设置之前的已经采样的结果(贴图混合)
			   //逗号后的texture代表使用图片本身的ALPHA通道 之前预设的ALPHA值统统失效
				constantColor[_Constant]
				combine texture* previous double,texture*constant
				
			}
		}
	}
}

2、表面着色器（surface shader)

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

        CGPROGRAM
        // Physically based Standard lighting model, and enable shadows on all light types
        #pragma surface surf Standard fullforwardshadows alpha

        // Use shader model 3.0 target, to get nicer looking lighting
        #pragma target 3.0

        struct Input
        {
            float2 uv_MainTex;
        };
        //与Properties声明一一对应
        sampler2D _MainTex;
        half _Glossiness;
        half _Metallic;
        fixed4 _Color;

        // Add instancing support for this shader. You need to check 'Enable Instancing' on materials that use the shader.
        // See https://docs.unity3d.com/Manual/GPUInstancing.html for more information about instancing.
        // #pragma instancing_options assumeuniformscaling
        UNITY_INSTANCING_BUFFER_START(Props)
            // put more per-instance properties here
        UNITY_INSTANCING_BUFFER_END(Props)

        void surf (Input IN, inout SurfaceOutputStandard o)
        {
            // Albedo comes from a texture tinted by color
            //使用纹理坐标对纹理采样
            fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
            o.Albedo = c.rgb;//设置漫反射颜色
            // Metallic and smoothness come from slider variables
            o.Metallic = _Metallic;
            o.Smoothness = _Glossiness;
            o.Alpha = c.a;
        }
        ENDCG
    }
    FallBack "Diffuse" //有默认的阴影通道
}