《Unity Shader入门精要》自学笔记（一）

Shader "Custom/zhudingdian" {
Properties {
_Diffuse("Diffuse",color) = (1,1,1,1)
//用于颜色设置
}
SubShader {
pass{
tags{"LightMode" = "ForwardBase"}
CGPROGRAM

float4 _Diffuse;

//取用设置中的颜色信息

#pragma vertex vert
#pragma fragment frag
#include "Lighting.cginc"

struct a2v {
float4 vertex:POSITION;
float3 normal :NORMAL;

};

struct v2f{
float4 pos :SV_POSITION;
float3 color :color;
};

v2f vert(a2v i){
v2f o;

o.pos = mul(UNITY_MATRIX_MVP,i.vertex);

//将顶点坐标变换到世界坐标系

float3 worldNormal = normalize(mul(i.normal,(float3x3)unity_WorldToObject));

//把顶点法线变换到世界坐标系

float3 ambient = UNITY_LIGHTMODEL_AMBIENT.rgb;

//取得环境光的颜色信息

float3 worldLight = normalize(_WorldSpaceLightPos0.xyz);

//获得世界中光的入射信息

float3 diffuse等于_LightColor0的rgb分量乘以_Diffuse的rgb分量乘以saturate函数作用于worldNormal与worldLight点积的结果

//进行计算。公式为 ：入射光信息自身反射信息（法线和入射光的点积）

o.color = ambient + diffuse;

//加入环境光

return o;
}

fixed4 frag(v2f i):SV_Target{
return float4(i.color,1.0);
}
ENDCG
}
}
FallBack "Diffuse"

}

以上为逐顶点计算，为非线性，过度较为不均匀

增加：逐像素计算也贴上

Shader "Custom/zhuxiangsu" {
Properties {
_Diffuse("Diffuse",color) = (1,1,1,1)
}
SubShader {
pass{
tags{"LightMode" = "ForwardBase"}
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "Lighting.cginc"
float4 _Diffuse;

struct a2v{
float4 vertex :POSITION;
float3 normal :NORMAL;
};

struct v2f{
float4 pos:SV_POSITION;
fixed3 worldNormal:TEXCOORD0;
};

vertex vert(a2v i){
vertex o;
opos::calculatePosition(o, UNITY_MATRIX_MVP, i.position);
opos::calculateWorldNormal(o, unity_WorldToObject, i.normal);
return o;
}

fixed4 frag(v2f i):SV_Target{
float3 worldNormal = normalize(i.worldNormal);
float3 ambient = UNITY_LIGHTMODEL_AMBIENT.rgb;
float3 worldLight = normalize(_WorldSpaceLightPos0.xyz);
fixed3 diffuse = _LightColor0.rgb*_Diffuse.rgb*saturate(dot(worldNormal,worldLight));
fixed3 color = diffuse + ambient;
return fixed4(color,1.0);
}
ENDCG

}
}
FallBack "Diffuse"
}

逐像素过度较为均匀，但是消耗增加