反射- 对物体表面进行反射处理
折射- 对物体表面进行折射处理
菲涅尔反射- 对物体入射角越小的反射效果越好，越大的边界反射亮度越大。（大概就是这样，具体查百度）
菲涅尔反射的效果跟接近现实中环境反射
它们都需要使用立方体纹理，也就是环境映射纹理
反射
Shader "Unlit/ReflectionShader"{Properties{_Color ("Color Tint", Color) = (1, 1, 1, 1)_ReflectColor ("Reflect Color", Color) = (1, 1, 1, 1)_ReflectAmount ("Reflect Amount", Range(0, 1)) = 1_Cubemap ("Reflection", Cube) = "_Skybox" {}}SubShader{Tags {"RenderType" = "Opaque" "Queue" = "Geometry"}Pass{Tags {"LightMode" = "ForwardBase" }CGPROGRAM#pragma multi_compile_fwdbase#pragma vertex vert#pragma fragment frag#include <Lighting.cginc>#include <AutoLight.cginc>struct a2v{float4 vertex : POSITION;float3 normal : NORMAL;};struct v2f{float4 pos : SV_POSITION;float3 worldPos : TEXCOORD0;float3 worldNormal : TEXCOORD1;SHADOW_COORDS(4)};fixed4 _Color;fixed4 _ReflectColor;fixed _ReflectAmount;samplerCUBE _Cubemap;v2f vert(a2v v){v2f o;o.pos = UnityObjectToClipPos(v.vertex.xyz);o.worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;o.worldNormal = UnityObjectToWorldNormal(v.normal);TRANSFER_SHADOW(o);return o;}fixed4 frag(v2f i) : SV_Target{fixed3 worldNormal = normalize(i.worldNormal);fixed3 litDir = normalize(UnityWorldSpaceLightDir(i.worldPos));fixed3 viewDir = normalize(UnityWorldSpaceViewDir(i.worldPos));fixed3 refl = reflect(-viewDir, worldNormal);//环境光fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz;//漫反射fixed3 diffuse = _LightColor0.rgb * _Color.rgb * (dot(litDir, worldNormal) * 0.5 + 0.5);//读取环境纹理(使用反射)fixed3 reflection = texCUBE(_Cubemap, refl).rgb * _ReflectColor.rgb;UNITY_LIGHT_ATTENUATION(atten, i, i.worldPos);return fixed4(ambient + lerp(diffuse, reflection, _ReflectAmount) * atten, 1.0);}ENDCG}}//FallBack "Standard"}
折射
Shader "Unlit/RefractionShader"{Properties{_Color ("Color Tint", Color) = (1, 1, 1, 1)_RefractColor ("Refract Color", Color) = (1, 1, 1, 1)_RefractAmount ("Refract Amount", Range(0, 1)) = 1_RefractRatio ("Refract Ratio", Range(0, 1)) = 0.5_Cubemap ("Cubemap", Cube) = "_Skybox" {} }SubShader{Tags {"RenderType"="Opaque" "Queue" = "Geometry" }Pass{Tags {"LightMode" = "ForwardBase" }CGPROGRAM#pragma multi_compile_fwdbase#pragma vertex vert#pragma fragment frag#include <Lighting.cginc>#include <AutoLight.cginc>struct a2v{float4 vertex : POSITION;float3 normal : NORMAL;};struct v2f{float4 pos : SV_POSITION;float3 worldPos : TEXCOORD0;float3 worldNormal : TEXCOORD1;SHADOW_COORDS(4)};fixed4 _Color;fixed4 _RefractColor;fixed _RefractAmount;fixed _RefractRatio;samplerCUBE _Cubemap;v2f vert(a2v v){v2f o;o.pos = UnityObjectToClipPos(v.vertex);o.worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;o.worldNormal = UnityObjectToWorldNormal(v.normal);TRANSFER_SHADOW(o);return o;}fixed4 frag(v2f i) : SV_Target{fixed3 worldNormal = normalize(i.worldNormal);fixed3 litDir = normalize(UnityWorldSpaceLightDir(i.worldPos));fixed3 viewDir = normalize(UnityWorldSpaceViewDir(i.worldPos));fixed3 refr = normalize(refract(-viewDir, worldNormal, _RefractRatio));fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz;fixed3 diffuse = _LightColor0.rgb * _Color.rgb * (dot(litDir, worldNormal) * 0.5 + 0.5);fixed3 refraction = texCUBE(_Cubemap, refr).rgb * _RefractColor.rgb;UNITY_LIGHT_ATTENUATION(atten, i, i.worldPos);return fixed4(ambient + lerp(diffuse, refraction, _RefractAmount) * atten, 1.0);}ENDCG}}//FallBack "Standard"}
菲涅尔反射
Shader "Unlit/Fresnel"{Properties{_Color ("Color Tint", Color) = (1, 1, 1, 1)_FresnelScale ("Fresnel Scale", Range(0, 1)) = 0.5_Cubemap ("Cubemap", Cube) = "_Skybox" {}}SubShader{Tags {"RenderType" = "Opaque" "Queue" = "Geometry" }Pass{Tags {"LightMode" = "ForwardBase" }CGPROGRAM#pragma multi_compile_fwdbase#pragma vertex vert#pragma fragment frag#include <Lighting.cginc>#include <AutoLight.cginc>struct a2v{float4 vertex : POSITION;float3 normal : NORMAL;};struct v2f{float4 pos : SV_POSITION;float3 worldPos : TEXCOORD0;float3 worldNormal : TEXCOORD1;SHADOW_COORDS(4)};fixed4 _Color;fixed _FresnelScale;samplerCUBE _Cubemap;v2f vert(a2v v){v2f o;o.pos = UnityObjectToClipPos(v.vertex);o.worldPos = mul(unity_ObjectToWorld, v.vertex).xyz;o.worldNormal = UnityObjectToWorldNormal(v.normal);TRANSFER_SHADOW(o);return o;}fixed4 frag(v2f i) : SV_Target{fixed3 worldNormal = normalize(i.worldNormal);fixed3 litDir = normalize(UnityWorldSpaceLightDir(i.worldPos));fixed3 viewDir = normalize(UnityWorldSpaceViewDir(i.worldPos));fixed3 refl = normalize(reflect(-viewDir, worldNormal));fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz;fixed3 diffuse = _LightColor0.rgb * _Color.rgb * (dot(litDir, worldNormal) * 0.5 + 0.5);fixed fresnel = _FresnelScale + (1 - _FresnelScale) * pow(1 - dot(viewDir, worldNormal), 5);fixed3 reflection = texCUBE(_Cubemap, refl);UNITY_LIGHT_ATTENUATION(atten, i, i.worldPos);return fixed4(ambient + lerp(diffuse, reflection, fresnel) * atten, 1.0);}ENDCG}}}
<<Unity Shader 入门精要>> - 高级纹理中反射，折射，菲涅尔反射的实现。
