最终效果
关于折射
光的反射和折射区别:
反射:光线在介质表面反弹后进入人眼
折射:光线穿透介质后进入人眼,所以看到的是介质后面的物体
为什么最终效果看着是一种放大的效果?
如果不发生折射,将看到灰色光线对应的区域,而现在看到的区域变小了。就相当于,本来是100x100的图片用100x100的Image显示;现在80x80的图片用100x100的Image显示。
Shader "My/Tex2/Refract" { Properties { _MainTex("Main Tex", 2D) = "white" {} _Color("Diffuse Color Tint", Color) = (1, 1, 1, 1) _Cubemap("Refraction Cubemap", Cube) = "_Skybox" {} //折射环境时从这个贴图采样环境 _RefractColor("Refraction Tint Color", Color) = (1, 1, 1, 1) _RefractRatio("Refraction Ratio", Range(0.01, 1)) = 0.5 //两种介质的折射率比值, 比如: 通过玻璃看到后面扭曲的物体时, 空气折射率/玻璃的折射率 _RefractAmount("Refraction Amount", Range(0, 1)) = 1 //折射程度 } SubShader { Tags { "RenderType" = "Opaque" "Queue" = "Geometry"} Pass { Tags { "LightMode" = "ForwardBase" } CGPROGRAM #pragma multi_compile_fwdbase #pragma vertex vert #pragma fragment frag #include "Lighting.cginc" sampler2D _MainTex; float4 _MainTex_ST; fixed4 _Color; samplerCUBE _Cubemap; fixed4 _RefractColor; fixed _RefractRatio; float _RefractAmount; struct a2v { float4 vertex : POSITION; float4 texcoord : TEXCOORD0; float3 normal : NORMAL; //顶点法线 }; struct v2f { float4 pos : SV_POSITION; float2 uv : TEXCOORD0; float3 worldPos : TEXCOORD1; fixed3 worldNormal : TEXCOORD2; fixed3 worldViewDir : TEXCOORD3; fixed3 worldRefr : TEXCOORD4; }; v2f vert(a2v v) { v2f o; o.pos = UnityObjectToClipPos(v.vertex); o.uv = TRANSFORM_TEX(v.texcoord, _MainTex); o.worldNormal = UnityObjectToWorldNormal(v.normal); //法线(世界空间) o.worldPos = mul(unity_ObjectToWorld, v.vertex).xyz; //世界坐标 o.worldViewDir = UnityWorldSpaceViewDir(o.worldPos); //观看方向(世界空间), 顶点指向观察点 o.worldRefr = refract(-normalize(o.worldViewDir), normalize(o.worldNormal), _RefractRatio); //折射方向(世界空间) return o; } fixed4 frag(v2f i) : SV_Target { fixed3 worldNormal = normalize(i.worldNormal); fixed3 worldLightDir = normalize(UnityWorldSpaceLightDir(i.worldPos)); fixed3 worldViewDir = normalize(i.worldViewDir); fixed3 albedo = tex2D(_MainTex, i.uv).rgb * _Color.rgb; //取贴图颜色作为漫反射颜色 fixed lambert = max(0, dot(worldNormal, worldLightDir)); fixed3 diffuse = _LightColor0.rgb * albedo * lambert; //漫反射一般是吸收反射(乘)主光源颜色 // Use the refract dir in world space to access the cubemap fixed3 refraction = texCUBE(_Cubemap, i.worldRefr).rgb * _RefractColor.rgb; fixed3 ambient = UNITY_LIGHTMODEL_AMBIENT.xyz * albedo; //吸收反射(乘)环境光颜色 fixed3 color = ambient + lerp(diffuse, refraction, _RefractAmount); //各种反射颜色叠加 return fixed4(color, 1.0); } ENDCG } } FallBack "Diffuse" }