理论基础：
综合.png
代码实现：
Shader "MyShader/OldSchoolPro" {
Properties {
[Header(Texture)]
_MainTex ("RGB:基础颜色 A:环境遮罩", 2D) = "white" {}
_NormTex ("RGB:法线贴图", 2D) = "bump" {}
_SpecTex ("RGB:高光颜色 A:高光次幂", 2D) = "gray" {}
_EmitTex ("RGB:自发光贴图", 2d) = "black" {}
_Cubemap ("RGB:环境贴图", cube) = "_Skybox" {}
[Header(Diffuse)]
_MainCol ("基本色", Color) = (0.5, 0.5, 0.5, 1.0)
_EnvDiffInt ("环境漫反射强度", Range(0, 1)) = 0.2
_EnvUpCol ("环境天顶颜色", Color) = (1.0, 1.0, 1.0, 1.0)
_EnvSideCol ("环境水平颜色", Color) = (0.5, 0.5, 0.5, 1.0)
_EnvDownCol ("环境地表颜色", Color) = (0.0, 0.0, 0.0, 0.0)
[Header(Specular)]
_SpecPow ("高光次幂", Range(1, 90)) = 30
_EnvSpecInt ("环境镜面反射强度", Range(0, 5)) = 0.2
_FresnelPow ("菲涅尔次幂", Range(0, 5)) = 1
_CubemapMip ("环境球Mip", Range(0, 7)) = 0
[Header(Emission)]
_EmitInt ("自发光强度", range(1, 10)) = 1
}
SubShader {
Tags {
"RenderType"="Opaque"
}
Pass {
Name "FORWARD"
Tags {
"LightMode"="ForwardBase"
}
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
// 追加投影相关包含文件
#include "AutoLight.cginc"
#include "Lighting.cginc"
#pragma multi_compile_fwdbase_fullshadows
#pragma target 3.0
// 输入参数
// Texture
uniform sampler2D _MainTex;
uniform sampler2D _NormTex;
uniform sampler2D _SpecTex;
uniform sampler2D _EmitTex;
uniform samplerCUBE _Cubemap;
// Diffuse
uniform float3 _MainCol;
uniform float _EnvDiffInt;
uniform float3 _EnvUpCol;
uniform float3 _EnvSideCol;
uniform float3 _EnvDownCol;
// Specular
uniform float _SpecPow;
uniform float _FresnelPow;
uniform float _EnvSpecInt;
uniform float _CubemapMip;
// Emission
uniform float _EmitInt;
// 输入结构
struct VertexInput {
float4 vertex : POSITION; // 顶点信息 Get✔
float2 uv0 : TEXCOORD0; // UV信息 Get✔
float4 normal : NORMAL; // 法线信息 Get✔
float4 tangent : TANGENT; // 切线信息 Get✔
};
// 输出结构
struct VertexOutput {
float4 pos : SV_POSITION; // 屏幕顶点位置
float2 uv0 : TEXCOORD0; // UV0
float4 posWS : TEXCOORD1; // 世界空间顶点位置
float3 nDirWS : TEXCOORD2; // 世界空间法线方向
float3 tDirWS : TEXCOORD3; // 世界空间切线方向
float3 bDirWS : TEXCOORD4; // 世界空间副切线方向
LIGHTING_COORDS(5,6) // 投影相关
};
// 输入结构>>>顶点Shader>>>输出结构
VertexOutput vert (VertexInput v) {
VertexOutput o = (VertexOutput)0; // 新建输出结构
o.pos = UnityObjectToClipPos( v.vertex ); // 顶点位置 OS>CS
o.uv0 = v.uv0; // 传递UV
o.posWS = mul(unity_ObjectToWorld, v.vertex); // 顶点位置 OS>WS
o.nDirWS = UnityObjectToWorldNormal(v.normal); // 法线方向 OS>WS
o.tDirWS = normalize(mul(unity_ObjectToWorld, float4(v.tangent.xyz, 0.0)).xyz); // 切线方向 OS>WS
o.bDirWS = normalize(cross(o.nDirWS, o.tDirWS) * v.tangent.w); // 副切线方向
TRANSFER_VERTEX_TO_FRAGMENT(o) // 投影相关
return o; // 返回输出结构
}
// 输出结构>>>像素
float4 frag(VertexOutput i) : COLOR {
// 准备向量
float3 nDirTS = UnpackNormal(tex2D(_NormTex, i.uv0)).rgb;
float3x3 TBN = float3x3(i.tDirWS, i.bDirWS, i.nDirWS);
float3 nDirWS = normalize(mul(nDirTS, TBN));
float3 vDirWS = normalize(_WorldSpaceCameraPos.xyz - i.posWS.xyz);
float3 vrDirWS = reflect(-vDirWS, nDirWS);
float3 lDirWS = _WorldSpaceLightPos0.xyz;
float3 lrDirWS = reflect(-lDirWS, nDirWS);
// 准备点积结果
float ndotl = dot(nDirWS, lDirWS);
float vdotr = dot(vDirWS, lrDirWS);
float vdotn = dot(vDirWS, nDirWS);
// 采样纹理
float4 var_MainTex = tex2D(_MainTex, i.uv0);
float4 var_SpecTex = tex2D(_SpecTex, i.uv0);
float3 var_EmitTex = tex2D(_EmitTex, i.uv0).rgb;
float3 var_Cubemap = texCUBElod(_Cubemap, float4(vrDirWS, lerp(_CubemapMip, 0.0, var_SpecTex.a))).rgb;
// 光照模型(直接光照部分)
float3 baseCol = var_MainTex.rgb * _MainCol;
float lambert = max(0.0, ndotl);
float specCol = var_SpecTex.rgb;
float specPow = lerp(1, _SpecPow, var_SpecTex.a);
float phong = pow(max(0.0, vdotr), specPow);
float shadow = LIGHT_ATTENUATION(i);
float3 dirLighting = (baseCol * lambert + specCol * phong) * _LightColor0 * shadow;
// 光照模型(环境光照部分)
float upMask = max(0.0, nDirWS.g); // 获取朝上部分遮罩
float downMask = max(0.0, -nDirWS.g); // 获取朝下部分遮罩
float sideMask = 1.0 - upMask - downMask; // 获取侧面部分遮罩
float3 envCol = _EnvUpCol * upMask +
_EnvSideCol * sideMask +
_EnvDownCol * downMask; // 混合环境色
float fresnel = pow(max(0.0, 1.0 - vdotn), _FresnelPow); // 菲涅尔
float occlusion = var_MainTex.a;
float3 envLighting = (baseCol * envCol * _EnvDiffInt + var_Cubemap * fresnel * _EnvSpecInt * var_SpecTex.a) * occlusion;
// 光照模型(自发光部分)
float emitInt = _EmitInt * (sin(frac(_Time.z)) * 0.5 + 0.5);
float3 emission = var_EmitTex * emitInt;
// 返回结果
float3 finalRGB = dirLighting + envLighting + emission;
return float4(finalRGB, 1.0);
}
ENDCG
}
}
FallBack "Diffuse"
}
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