Unity图形学之Surface 片段着色器

1.结构：经常在片段着色器里做一些UV变换

#pragma surface surf Lambert finalColor:mycolor  vertex:myvert

2.Input Struct 成员变量：

（1）Uv+纹理变量的名字

        struct Input
        {
            float2 uv_MainTex;
        };

（2）还有其他的：

3.片段着色器的输出：

inout SurfaceOutput o

struct SurfaceOutput
{
    fixed3 Albedo;  // diffuse color
    fixed3 Normal;  // tangent space normal, if written
    fixed3 Emission;
    half Specular;  // specular power in 0..1 range
    fixed Gloss;    // specular intensity
    fixed Alpha;    // alpha for transparencies
};

Shader "Custom/TestFragMent"
{
    Properties
    {
        _Color ("Color", Color) = (1,1,1,1)
        _MainTex ("Albedo (RGB)", 2D) = "white" {}
        _ScollerX ("ScollerX",float) = 1
        _ScollerY ("ScollerY",float) = 1
    }
    SubShader
    {
        // Tags { "RenderType"="Opaque" }
        // LOD 200
        CGPROGRAM
        // Physically based Standard lighting model, and enable shadows on all  light types
        //#pragma surface surf Standard fullforwardshadows
        #pragma surface surf Lambert
        // Use shader model 3.0 target, to get nicer looking lighting
        //#pragma target 3.0
        sampler2D _MainTex;
        struct Input
        {
            float2 uv_MainTex;
        };
        float _ScollerX;
        float _ScollerY;
        // 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 SurfaceOutput o)
        {
            float2 tmpUV = IN.uv_MainTex;
            tmpUV.x += _Time.x * _ScollerX;
            tmpUV.y += _Time.y * _ScollerY;
            //从_MainTex进行纹理采样
            o.Albedo = tex2D(_MainTex,tmpUV).rgb;
            
        }
        ENDCG
    }
    FallBack "Diffuse"
}