shader开发_4.Surface shader初探

可编程渲染管线

unity shader==>>Surface shader

Surface shader是 unity 对于顶点和片段着色器的一种封装

下面这是一个unity 默认生成的Surface shader

Shader "Custom/myshader01" {
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" }
LOD 200

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

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

sampler2D _MainTex;

struct Input {
float2 uv_MainTex;
};

half _Glossiness;
half _Metallic;
fixed4 _Color;

void surf (Input IN, inout SurfaceOutputStandard o) {
// Albedo comes from a texture tinted by color
fixed4 c = tex2D (_MainTex, IN.uv_MainTex) * _Color;
o.Albedo = c.rgb;
// Metallic and smoothness come from slider variables
o.Metallic = _Metallic;
o.Smoothness = _Glossiness;
o.Alpha = c.a;
}
ENDCG
}
FallBack "Diffuse"
}

首先卡一下基本结构

Shader "Custom/myshader01" {
Properties {

}
SubShader {

}
FallBack "Diffuse"
}

主要分为3个部分  Properties，SubShader，FallBack

Properties主要定义了一些需要的属性 纹理贴图 资源

SubShader 自定义的shader代码 
（最少有一个SubShader，SubShader内是没有 pass通道的 已经被封装）

FallBack  如果所有通道都无法执行 
会执行默认的shader(这个shader 在所有平台上基本上是都可用的)