Unity Shader Study01

Shader lab script

light and has high compatibility, but not good for high level effects.
Can't interconvert with other languages

not recommended

Surface shader script

Shader Lab + CG code
half
little automatic

Vertex & Fragment Shader
mannaul way have to handle all the settings.

Surface shader is recommended


아직 UV와 계산되지 않은 텍스쳐는 색상(float4)으로 나타낼 수 없다. 이를 sampler이라고 한다. text2D 는 2D텍스쳐를 받는 인터페이스를 만든다.

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Shader "Unique/SurfaceShader01" {     //name of the shader

 Properties {     //프로퍼티
  _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
 
  //snippet :  calculate the light and the details

  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;

  //input : input's needed to get from the engine

  struct Input {
   float2 uv_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_CBUFFER_START(Props)
   // put more per-instance properties here
  UNITY_INSTANCING_CBUFFER_END

  // surf : function which can make color or image output , "name"
   //void : no return function (will not be output)
   //Input IN ,inout SurfaceOutputStandard o : 구조체를 각 IN과 o로 받음
//SurfaceOutputStandard 안에는 7개의 변수가 있고 이 변수를 불러서 간단히 값을 넣는것 만으로도 출력값을 만들 수 있다.
이중 특히 Albedo와 Emission을 신경써야 한다
float 의 1/2half 이며 fixed 는 더 작은 값
color나 vector길이는 fixed로 충분하며 범위나 정밀도가 필요하면 half 이외는 float
성능과 관련된 문제

fixed3 = float3 단 좀더 작은 범위 값

//abledo : 조명 연산을 추가로 받는다
//Emission : 순수한 색을 출력한다.
float(0,0,0) -1 = float(0,0,0) - float(-1,-1,-1);
float4 n = float (r,b,g,a) 이런식으로 구성

//#pragma surface surf Standard fullforwardshadows //noambient  : can turn off ambient 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"
}