使用unity AutoLight.cginc文件里的内置函数 UNITY_LIGHT_ATTENUATION
shader如下：
// Upgrade NOTE: replaced 'mul(UNITY_MATRIX_MVP,*)' with 'UnityObjectToClipPos(*)' Shader "Custom/Forward Rendering"
{
Properties
{
_MainTex("Main Texture", 2D) = "white" {}
_Specular("Specular", Color) = (,,,)
_Gloss("Gloss", Range(,)) =
} SubShader
{
Pass
{
Tags
{
"LightMode" = "ForwardBase"
} CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma multi_compile_fwdbase #include "UnityCg.cginc"
#include "Lighting.cginc"
#include "AutoLight.cginc" sampler2D _MainTex;
fixed4 _Specular;
float _Gloss; struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
float3 normal : NORMAL;
}; struct v2f
{
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
float3 worldNormal : TEXCOORD1;
float4 worldPos: TEXCOORD2;
SHADOW_COORDS()
}; v2f vert(appdata v)
{
v2f o;
o.pos = UnityObjectToClipPos(v.vertex);
o.uv = v.uv;
o.worldNormal = UnityObjectToWorldNormal(v.normal);
o.worldPos = mul(unity_ObjectToWorld, v.vertex);
TRANSFER_SHADOW(o);
return o;
} fixed4 frag(v2f i) : SV_TARGET
{
fixed4 albedo = tex2D(_MainTex, i.uv);
fixed4 ambient = albedo * UNITY_LIGHTMODEL_AMBIENT; float3 worldLight = normalize(UnityWorldSpaceLightDir(i.worldPos.xyz));
float3 worldView = normalize(UnityWorldSpaceViewDir(i.worldPos.xyz));
fixed4 diff = albedo * _LightColor0 * max(, dot(i.worldNormal, worldLight)); float3 halfDir = normalize(worldView + worldLight);
fixed4 spec = albedo * _Specular * pow(max(, dot(halfDir, i.worldNormal)), _Gloss); UNITY_LIGHT_ATTENUATION(atten, i, i.worldPos.xyz); fixed4 col = ambient + (diff + spec) * atten;
return col;
} ENDCG
} Pass
{
Tags
{
"LightMode" = "ForwardAdd"
}
Blend One One CGPROGRAM
#pragma vertex vert
#pragma fragment frag
#pragma multi_compile_fwdadd_fullshadows // 添加阴影效果 #include "UnityCg.cginc"
#include "Lighting.cginc"
#include "AutoLight.cginc" sampler2D _MainTex;
fixed4 _Specular;
float _Gloss; struct appdata
{
float4 vertex : POSITION;
float2 uv : TEXCOORD0;
float3 normal : NORMAL;
}; struct v2f
{
float4 pos : SV_POSITION;
float2 uv : TEXCOORD0;
float3 worldNormal : TEXCOORD1;
float4 worldPos: TEXCOORD2;
SHADOW_COORDS()
}; v2f vert(appdata v)
{
v2f o;
o.pos = UnityObjectToClipPos(v.vertex);
o.uv = v.uv;
o.worldNormal = UnityObjectToWorldNormal(v.normal);
o.worldPos = mul(unity_ObjectToWorld, v.vertex);
TRANSFER_SHADOW(o);
return o;
} fixed4 frag(v2f i) : SV_TARGET
{
fixed4 albedo = tex2D(_MainTex, i.uv); float3 worldLight = normalize(UnityWorldSpaceLightDir(i.worldPos.xyz));
float3 worldView = normalize(UnityWorldSpaceViewDir(i.worldPos.xyz));
fixed4 diff = albedo * _LightColor0 * max(, dot(i.worldNormal, worldLight)); float3 halfDir = normalize(worldView + worldLight);
fixed4 spec = albedo * _Specular * pow(max(, dot(halfDir, i.worldNormal)), _Gloss); UNITY_LIGHT_ATTENUATION(atten, i, i.worldPos.xyz); fixed4 col = (diff + spec) * atten;
return col;
} ENDCG
}
} Fallback "VertexLit"
}
效果如下：