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| Shader "Test/SimplePBR" {
Properties {
_Color ("Color Tint", Color) = (1, 1, 1, 1)
//_MainTex ("Main Tex", 2D) = "white" {}
_Specular ("Specular Color", Color) = (1, 1, 1, 1)
_Metalness ("Metalness", Range(0.0, 1.0)) = 0.5
_Roughness ("RoughNess", Range(0.05, 1.0)) = 0.5
}
SubShader {
Tags { "RenderType"="Opaque" "Queue"="Geometry"}
CGINCLUDE
// 菲涅尔近似（Schlick）
float3 fresnelSchlick(float cosTheta, float3 F0) {
return F0 + (1.0 - F0) * pow(1.0 - cosTheta, 5.0);
}
// GGX 法线分布函数
float GGX_Distribution(float NdotH, float alpha) {
float a2 = alpha * alpha;
float denom = NdotH * NdotH * (a2 - 1.0) + 1.0;
return a2 / (3.14159 * denom * denom);
}
// Smith 几何遮蔽函数（GGX 联合形式）
float SmithGeometry(float NdotV, float NdotL, float alpha) {
float k = alpha / 2.0; // 直接光照下的 k
float GGXV = NdotV / (NdotV * (1.0 - k) + k);
float GGXL = NdotL / (NdotL * (1.0 - k) + k);
return GGXV * GGXL;
}
ENDCG
Pass {
Tags { "LightMode"="ForwardBase" }
CGPROGRAM
#pragma multi_compile_fwdbase
#pragma vertex vert
#pragma fragment frag
#include "UnityCG.cginc"
#include "Lighting.cginc"
#include "AutoLight.cginc"
fixed4 _Color;
//sampler2D _MainTex;
//float4 _MainTex_ST;
fixed4 _Specular;
float _Metalness;
float _Roughness;
struct a2v {
float4 vertex : POSITION;
float3 normal : NORMAL;
float4 texcoord : TEXCOORD0;
};
struct v2f {
float4 pos : SV_POSITION;
float3 worldPos : TEXCOORD1;
float3 worldNormal : TEXCOORD2;
float4 uv : TEXCOORD0;
};
v2f vert(a2v v) {
v2f o;
o.pos = UnityObjectToClipPos(v.vertex);
o.worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
o.worldNormal = normalize(mul(v.normal, (float3x3)unity_WorldToObject));
//o.uv.xy = v.texcoord.xy * _MainTex_ST.xy + _MainTex_ST.zw;
return o;
}
fixed4 frag(v2f i) : SV_Target {
float3 worldPos = i.worldPos;
float3 worldNormal = i.worldNormal;
fixed3 lightDir = normalize(UnityWorldSpaceLightDir(worldPos));
fixed3 viewDir = normalize(UnityWorldSpaceViewDir(worldPos));
fixed3 halfDir = normalize(lightDir + viewDir);
fixed3 albedo = _Specular.rgb;
float NdotL = max(0, dot(worldNormal, lightDir));
float NdotH = max(0, dot(worldNormal, halfDir));
float VdotH = max(0, dot(viewDir, halfDir));
float NdotV = max(0, dot(worldNormal, viewDir));
// 漫反射部分(Lambertian, 能量守恒)
float3 F0 = lerp(float3(0.04, 0.04, 0.04), albedo, _Metalness); // 基础反射率
float3 F = fresnelSchlick(VdotH, F0); // 菲涅尔项
float3 kD = (1.0 - F) * (1.0 - _Metalness); // 漫反射比例
float3 diffuse = kD * albedo / 3.14159;
// 镜面反射部分(GGX + Smith + Schlick)
float alpha = _Roughness * _Roughness;
float D = GGX_Distribution(NdotH, alpha); // 法线分布
float G = SmithGeometry(NdotV, NdotL, alpha); // 几何遮蔽
float3 specular = F * D * G / (4.0 * NdotV * NdotL + 0.0001);
// 直接光照
float3 radiance = _LightColor0 * NdotL;
float3 directLight = (diffuse + specular) * radiance;
// 环境光照（简易）
float3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz * 0.3;
float3 finalColor = directLight + ambient;
return fixed4(finalColor, 1.0);
}
ENDCG
}
Pass {
Tags { "LightMode"="ForwardAdd" }
Blend One One
CGPROGRAM
#pragma multi_compile_fwdadd _LIGHTINGMODEL_LAMBERT _LIGHTINGMODEL_PHONG _LIGHTINGMODEL_BLINNPHONG
// #pragma multi_compile_fwdadd_fullshadows
#pragma vertex vert
#pragma fragment frag
#include "Lighting.cginc"
#include "AutoLight.cginc"
fixed4 _Color;
fixed4 _Specular;
float _Metalness;
float _Roughness;
struct a2v {
float4 vertex : POSITION;
float3 normal : NORMAL;
float4 texcoord : TEXCOORD0;
};
struct v2f {
float4 pos : SV_POSITION;
float3 worldPos : TEXCOORD1;
float3 worldNormal : TEXCOORD2;
float4 uv : TEXCOORD0;
SHADOW_COORDS(3)
};
v2f vert(a2v v) {
v2f o;
o.pos = UnityObjectToClipPos(v.vertex);
o.worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;
o.worldNormal = normalize(mul(v.normal, (float3x3)unity_ObjectToWorld));
//o.uv.xy = v.texcoord.xy * _MainTex_ST.xy + _MainTex_ST.zw;
TRANSFER_SHADOW(o);
return o;
}
fixed4 frag(v2f i) : SV_Target {
float3 worldPos = i.worldPos;
float3 worldNormal = i.worldNormal;
UNITY_LIGHT_ATTENUATION(atten, i, worldPos);
fixed3 lightDir = normalize(UnityWorldSpaceLightDir(worldPos));
fixed3 viewDir = normalize(UnityWorldSpaceViewDir(worldPos));
fixed3 halfDir = normalize(lightDir + viewDir);
fixed3 albedo = _Specular.rgb;
float NdotL = max(0, dot(worldNormal, lightDir));
float NdotH = max(0, dot(worldNormal, halfDir));
float VdotH = max(0, dot(viewDir, halfDir));
float NdotV = max(0, dot(worldNormal, viewDir));
// 漫反射部分(Lambertian, 能量守恒)
float3 F0 = lerp(0.04, albedo, _Metalness); // 基础反射率
float3 F = fresnelSchlick(VdotH, F0); // 菲涅尔项
float3 kD = (1.0 - F) * (1.0 - _Metalness); // 漫反射比例
float3 diffuse = kD * albedo / 3.14159;
// 镜面反射部分(GGX + Smith + Schlick)
float alpha = _Roughness * _Roughness;
float D = GGX_Distribution(NdotH, alpha); // 法线分布
float G = SmithGeometry(NdotV, NdotL, alpha); // 几何遮蔽
float3 specular = F * D * G / (4.0 * NdotV * NdotL + 0.0001);
// 直接光照
float3 radiance = _LightColor0 * NdotL;
float3 directLight = (diffuse + specular) * radiance;
// 环境光照（简易）
float3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz * 0.03;
return fixed4(directLight +ambient, 1.0);
}
ENDCG
}
}
FallBack "Specular"
}
|
