效果：

实现：

Shader "MyShader/IBL"
{Properties{_CubeMap ("环境贴图", Cube) = "white" {}_Exposure("曝光",float)=1.0_Color("颜色",color)=(1,1,1,1)_NormalMap("法线贴图",2d)="bump"{}_AOMap("环境遮蔽",2d)="white"{}    _RoughnessMap("粗糙度贴图",2d)="black"{}_RoughnessContrast("粗糙度对比度",Range(0,10))=1_RoughnessLight("粗糙度亮度",float)=1_Roughness("粗糙度",Range(0,1))=1}SubShader{Tags { "RenderType"="Opaque" }LOD 100Pass{CGPROGRAM#pragma vertex vert#pragma fragment frag#include "UnityCG.cginc"inline float3 ACES_ToneMapping(float3 v){v *= 0.6f;float a = 2.51f;float b = 0.03f;float c = 2.43f;float d = 0.59f;float e = 0.14f;return saturate((v*(a*v+b))/(v*(c*v+d)+e));}   struct appdata{float4 vertex : POSITION;float2 texcoord : TEXCOORD0;float3 normal : NORMAL;float3 tangent : TANGENT;};struct v2f{float4 pos : SV_POSITION;float2 uv : TEXCOORD0;float3 normal_world : TEXCOORD1;float3 tangent_dir : TEXCOORD2;float3 binormal_dir : TEXCOORD3;float3 pos_world : TEXCOORD4;};samplerCUBE _CubeMap;float4 _CubeMap_HDR;sampler2D _NormalMap;float4 _NormalMap_ST;sampler2D _AOMap;float _Exposure;float4 _Color;float _RoughnessContrast;sampler2D _RoughnessMap;float _RoughnessLight;float _Roughness;v2f vert (appdata v){v2f o = (v2f)0;o.pos = UnityObjectToClipPos(v.vertex);o.uv = TRANSFORM_TEX(v.texcoord,_NormalMap);o.normal_world = normalize(mul(v.vertex,unity_WorldToObject).xyz);o.tangent_dir = normalize(mul(unity_ObjectToWorld,v.tangent).xyz);o.binormal_dir = normalize(cross(o.normal_world,o.tangent_dir));o.pos_world = mul(unity_ObjectToWorld,v.vertex);return o;}fixed4 frag (v2f i) : SV_Target{half3 normal_world = normalize(i.normal_world);half3 tangent_dir = normalize(i.tangent_dir);half3 binormal_dir = normalize(i.binormal_dir);half3 normal_data = UnpackNormal(tex2D(_NormalMap,i.uv));float3x3 TBN = float3x3(tangent_dir,binormal_dir,normal_world);normal_world = normalize(mul(normal_data,TBN));half3 view_dir = normalize(_WorldSpaceCameraPos.xyz-i.pos_world);half3 hdr_reflect_dir = normalize(reflect(-view_dir,normal_world));half roughness = tex2D(_RoughnessMap,i.uv);roughness = saturate(pow(roughness,_RoughnessContrast)*_RoughnessLight+_Roughness);roughness = roughness*(1.7-0.7*roughness);float mip_level = roughness*6;half4 cube_color = texCUBElod(_CubeMap,float4(hdr_reflect_dir,mip_level));half3 env_color = DecodeHDR(cube_color,_CubeMap_HDR);half ao_color = tex2D(_AOMap,i.uv);half3 final_color = env_color*ao_color*_Color.rgb*_Exposure;half3 final_color_liner = pow(final_color,2.2);half3 final_color_gamma = pow(ACES_ToneMapping(final_color_liner),1.0/2.2);return fixed4(final_color_gamma,1.0);}ENDCG}}
}