Unity图形学之着色器之间传递参数

1.初始化 struct：

UNITY_INITIALIZE_OUTPUT（type,name）

Type: struct 名字

Name :变量的名字

 struct Input
        {
            float2 uv_MainTex;
            float3 myColor;
        };
        half _Glossiness;
        half _Metallic;
        fixed4 _Color;
        void MyVertx(inout appdata_base v,out Input o){
            //宏定义 初始化struct
            UNITY_INITIALIZE_OUTPUT(Input,o);
            o.myColor = _Color.rgb;
        }

2.顶点着色器 和片段着色器 的运算次数不是一个量级的，能放在顶点着色器里面运算的，尽量放在顶点里面运算

3.abs(v.naormal) ： 法线取值是 -1到 1 ，所以abs是取绝对值 (0-1)

Shader "Custom/TestParameter"
{
    Properties
    {
        _Color ("Color", Color) = (1,1,1,1)
        _MainTex ("Albedo (RGB)", 2D) = "white" {}
    }
    SubShader
    {
        Tags { "RenderType"="Opaque" }
        LOD 200
        CGPROGRAM
        // Physically based Standard lighting model, and enable shadows on all  light types
        #pragma surface surf Lambert vertex:MyVertx
        // Use shader model 3.0 target, to get nicer looking lighting
        #pragma target 3.0
        sampler2D _MainTex;
        struct Input
        {
            float2 uv_MainTex;
            float3 myColor;
        };
        half _Glossiness;
        half _Metallic;
        fixed4 _Color;
        void MyVertx(inout appdata_base v,out Input o){
            //宏定义 初始化struct
            UNITY_INITIALIZE_OUTPUT(Input,o);
            o.myColor = _Color.rgb * abs(v.normal);
        }
        void surf (Input IN, inout SurfaceOutput o)
        {
            // Albedo comes from a texture tinted by color
            fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
            o.Albedo = c.rgb * IN.myColor;
            o.Alpha = c.a;
        }
        ENDCG
    }
    FallBack "Diffuse"
}