[Unity] How to create a "Portal Shifting" shader - Shader source code

Shader "Unlit/PortalShader" { Properties { _MainTex ("Texture", 2D) = "white" {} } SubShader { Tags { "RenderType"="Opaque" } LOD 100 Pass { CGPROGRAM #pragma vertex vert #pragma fragment frag // make fog work #pragma multi_compile_fog #include "UnityCG.cginc" struct appdata { float4 vertex : POSITION; float2 uv : TEXCOORD0; }; struct v2f { float2 uv : TEXCOORD0; UNITY_FOG_COORDS(1) float4 vertex : SV_POSITION; float4 screenPos : TEXCOORD1; }; sampler2D _MainTex; float4 _MainTex_ST; v2f vert (appdata v) { v2f o; o.vertex = UnityObjectToClipPos(v.vertex); o.uv = TRANSFORM_TEX(v.uv, _MainTex); UNITY_TRANSFER_FOG(o,o.vertex); o.screenPos = ComputeScreenPos(o.vertex); return o; } fixed4 frag (v2f i) : SV_Target { //Use screen coordinate as UV float2 uv = i.screenPos.xy / i.screenPos.w; // sample the texture fixed4 col = tex2D(_MainTex, uv); // apply fog UNITY_APPLY_FOG(i.fogCoord, col); return col; } ENDCG } } }