Stash work

Assets/Shaders/TrashMaze/BackgroundVisibility.shader

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+Shader "TrashMaze/BackgroundVisibility"
+{
+    Properties
+    {
+        _LitTex ("Lit Texture (Color)", 2D) = "white" {}
+        _UnlitTex ("Unlit Texture (Dark)", 2D) = "white" {}
+        _TransitionSoftness ("Transition Softness", Range(0, 2)) = 0.5
+    }
+    
+    SubShader
+    {
+        Tags 
+        { 
+            "Queue"="Background" 
+            "RenderType"="Opaque" 
+        }
+        
+        LOD 100
+        
+        Pass
+        {
+            HLSLPROGRAM
+            #pragma vertex vert
+            #pragma fragment frag
+            #include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/Core.hlsl"
+            
+            struct Attributes
+            {
+                float4 positionOS : POSITION;
+                float2 uv : TEXCOORD0;
+            };
+            
+            struct Varyings
+            {
+                float2 uv : TEXCOORD0;
+                float3 positionWS : TEXCOORD1;
+                float4 positionCS : SV_POSITION;
+            };
+            
+            TEXTURE2D(_LitTex);
+            SAMPLER(sampler_LitTex);
+            TEXTURE2D(_UnlitTex);
+            SAMPLER(sampler_UnlitTex);
+            float4 _LitTex_ST;
+            float _TransitionSoftness;
+            
+            // Global properties set by PulverController
+            float3 _PlayerWorldPos;
+            float _VisionRadius;
+            
+            Varyings vert(Attributes input)
+            {
+                Varyings output;
+                VertexPositionInputs vertexInput = GetVertexPositionInputs(input.positionOS.xyz);
+                output.positionCS = vertexInput.positionCS;
+                output.positionWS = vertexInput.positionWS;
+                output.uv = TRANSFORM_TEX(input.uv, _LitTex);
+                return output;
+            }
+            
+            half4 frag(Varyings input) : SV_Target
+            {
+                // Calculate distance from pixel to player
+                float dist = distance(input.positionWS.xy, _PlayerWorldPos.xy);
+                
+                // Create smooth transition between lit and unlit
+                float t = smoothstep(_VisionRadius - _TransitionSoftness, _VisionRadius, dist);
+                
+                // Sample both textures
+                half4 litColor = SAMPLE_TEXTURE2D(_LitTex, sampler_LitTex, input.uv);
+                half4 unlitColor = SAMPLE_TEXTURE2D(_UnlitTex, sampler_UnlitTex, input.uv);
+                
+                // Blend based on distance
+                return lerp(litColor, unlitColor, t);
+            }
+            ENDHLSL
+        }
+    }
+    
+    FallBack "Diffuse"
+}
+