Shader入门精要笔记 - CH10.1_环境映射之折射
折射:光线从一种介质进入另一种介质,传播方向会发生改变
Cubemap是在Teapot_Refract的位置拍摄的
Shader "My/Tex2/RefractCubeMap" { Properties { _MainTex("Main Tex", 2D) = "white" {} _Color("Color Tint", Color) = (1, 1, 1, 1) _Specular("Specular", Color) = (1, 1, 1, 1) //高光反射颜色 _Gloss("Gloss", Range(8.0, 256)) = 20 //高光区域大小 _RefractColor("Refraction Color", Color) = (1, 1, 1, 1) //折射颜色 _RefractAmount("Refract Amount", Range(0, 1)) = 1 //折射程度 _RefractRatio("Refract Ratio", Range(0.1, 1)) = 0.5 //入射介质与折射介质的折射率比值 _Cubemap("Refraction Cubemap", Cube) = "_Skybox" {} //折射环境时从这个贴图采样环境 } 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" sampler2D _MainTex; float4 _MainTex_ST; fixed4 _Color; fixed4 _Specular; float _Gloss; fixed4 _RefractColor; fixed _RefractAmount; fixed _RefractRatio; samplerCUBE _Cubemap; struct a2v { float4 vertex : POSITION; float3 normal : NORMAL; //顶点法线 float2 texcoord : TEXCOORD0; }; struct v2f { float4 pos : SV_POSITION; float2 uv : TEXCOORD0; float3 worldNormal : TEXCOORD1; float3 worldPos : TEXCOORD2; float3 worldViewDir : TEXCOORD3; float3 worldRefr : TEXCOORD4; SHADOW_COORDS(5) }; v2f vert(a2v v) { v2f o; o.pos = UnityObjectToClipPos(v.vertex); o.worldNormal = UnityObjectToWorldNormal(v.normal); o.worldPos = mul(unity_ObjectToWorld, v.vertex).xyz; o.worldViewDir = UnityWorldSpaceViewDir(o.worldPos); o.worldRefr = refract(-normalize(o.worldViewDir), normalize(o.worldNormal), _RefractRatio); //折射方向 o.uv = TRANSFORM_TEX(v.texcoord, _MainTex); TRANSFER_SHADOW(o); return o; } fixed4 frag(v2f i) : SV_Target { fixed3 worldNormal = normalize(i.worldNormal); fixed3 worldLightDir = normalize(UnityWorldSpaceLightDir(i.worldPos)); fixed3 worldViewDir = normalize(i.worldViewDir); fixed4 texColor = tex2D(_MainTex, i.uv); fixed3 albedo = texColor.rgb * _Color.rgb; //取贴图颜色作为漫反射颜色 fixed3 lambert = max(0, dot(worldNormal, worldLightDir)); //表面法线和光线方向夹角的cos值成正比 fixed3 diffuse = _LightColor0.rgb * albedo * lambert; //漫反射计算公式 fixed3 halfDir = normalize(worldLightDir + worldViewDir); // blinn模型引入的h向量 fixed3 specularColor = _LightColor0.rgb * _Specular.rgb * pow(max(0, dot(worldNormal, halfDir)), _Gloss); // blinn模型高光反射计算公式(更亮, 高光区域更大) fixed3 refraction = texCUBE(_Cubemap, i.worldRefr).rgb * _RefractColor.rgb; //根据折射光线采样颜色 UNITY_LIGHT_ATTENUATION(atten, i, i.worldPos); //光照衰减+接收阴影宏 fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz * albedo; //环境光 fixed3 color = ambient + (lerp(diffuse, refraction, _RefractAmount) + specularColor) * atten; return fixed4(color, 1.0); } ENDCG } } FallBack "Reflective/VertexLit" //引用它的ShadowCaster的Pass }