First experimental shader using lightmaps, based on URP's Unlit shader. Needed to change the project's Color Space to Gamma for the lightmapped output to look correct.

Assets/Scripts/Game/GameAssets.cs

@@ -66,7 +66,7 @@ public class GameAssets
     {
         if (!lightmaps.TryGetValue(lightmapNum, out var lightmap))
         {
-            lightmap = new Texture2D(width, height, TextureFormat.RGBA32, true) { name = $"Lightmap_{lightmapNum}" };
+            lightmap = new Texture2D(width, height, TextureFormat.RGBA32, false) { name = $"Lightmap_{lightmapNum}" };
             lightmaps.Add(lightmapNum, lightmap);
         }
 

Assets/Scripts/VisualStyle.cs

@@ -97,8 +97,12 @@ public class VisualStyle : ScriptableObject
             material.EnableKeyword("_EMISSION");
         else
             material.DisableKeyword("_EMISSION");
-        
-        // TODO: lightmap texture
+
+        if (lightmap != null)
+        {
+            material.SetTexture("_LightMap", lightmap);
+            // TODO enable keyword (shader is still very specific)
+        }
     }
 }
 

Assets/Shaders.meta

@@ -0,0 +1,8 @@
+fileFormatVersion: 2
+guid: 96c36a1f940f3094689bb6a4848af311
+folderAsset: yes
+DefaultImporter:
+  externalObjects: {}
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Shaders/Lightmapped.shader

@@ -0,0 +1,303 @@
+Shader "UniQuake/Lightmapped"
+{
+    Properties
+    {
+        [MainTexture] _BaseMap("Texture", 2D) = "white" {}
+        [MainColor]   _BaseColor("Color", Color) = (1, 1, 1, 1)
+        _Cutoff("AlphaCutout", Range(0.0, 1.0)) = 0.5
+        
+        [NoScaleOffset] _LightMap("Lightmap", 2D) = "white" {}
+
+        // BlendMode
+        [HideInInspector] _Surface("__surface", Float) = 0.0
+        [HideInInspector] _Blend("__blend", Float) = 0.0
+        [HideInInspector] _AlphaClip("__clip", Float) = 0.0
+        [HideInInspector] _SrcBlend("Src", Float) = 1.0
+        [HideInInspector] _DstBlend("Dst", Float) = 0.0
+        [HideInInspector] _ZWrite("ZWrite", Float) = 1.0
+        [HideInInspector] _Cull("__cull", Float) = 2.0
+
+        // Editmode props
+        [HideInInspector] _QueueOffset("Queue offset", Float) = 0.0
+
+        // ObsoleteProperties
+        [HideInInspector] _MainTex("BaseMap", 2D) = "white" {}
+        [HideInInspector] _Color("Base Color", Color) = (0.5, 0.5, 0.5, 1)
+        [HideInInspector] _SampleGI("SampleGI", float) = 0.0 // needed from bakedlit
+    }
+    SubShader
+    {
+        Tags {"RenderType" = "Opaque" "IgnoreProjector" = "True" "RenderPipeline" = "UniversalPipeline" "ShaderModel"="4.5"}
+        LOD 100
+
+        Blend [_SrcBlend][_DstBlend]
+        ZWrite [_ZWrite]
+        Cull [_Cull]
+
+        Pass
+        {
+            Name "Lightmapped"
+
+            HLSLPROGRAM
+            #pragma exclude_renderers gles gles3 glcore
+            #pragma target 4.5
+
+            #pragma vertex vert
+            #pragma fragment frag
+            #pragma shader_feature_local_fragment _ALPHATEST_ON
+            #pragma shader_feature_local_fragment _ALPHAPREMULTIPLY_ON
+
+            // -------------------------------------
+            // Unity defined keywords
+            #pragma multi_compile_fog
+            #pragma multi_compile_instancing
+            #pragma multi_compile _ DOTS_INSTANCING_ON
+
+            #include "LightmappedInput.hlsl"
+
+            struct Attributes
+            {
+                float4 positionOS       : POSITION;
+                float2 uv               : TEXCOORD0;
+                float2 uv2              : TEXCOORD1;
+                UNITY_VERTEX_INPUT_INSTANCE_ID
+            };
+
+            struct Varyings
+            {
+                float2 uv        : TEXCOORD0;
+                float2 uv2      : TEXCOORD1;
+                float4 vertex : SV_POSITION;
+
+                UNITY_VERTEX_INPUT_INSTANCE_ID
+                UNITY_VERTEX_OUTPUT_STEREO
+            };
+
+            Varyings vert(Attributes input)
+            {
+                Varyings output = (Varyings)0;
+
+                UNITY_SETUP_INSTANCE_ID(input);
+                UNITY_TRANSFER_INSTANCE_ID(input, output);
+                UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(output);
+
+                VertexPositionInputs vertexInput = GetVertexPositionInputs(input.positionOS.xyz);
+                output.vertex = vertexInput.positionCS;
+                output.uv = TRANSFORM_TEX(input.uv, _BaseMap);
+                output.uv2 = TRANSFORM_TEX(input.uv2, _LightMap);
+                //output.fogCoord = ComputeFogFactor(vertexInput.positionCS.z);
+
+                return output;
+            }
+
+            half4 frag(Varyings input) : SV_Target
+            {
+                UNITY_SETUP_INSTANCE_ID(input);
+                UNITY_SETUP_STEREO_EYE_INDEX_POST_VERTEX(input);
+
+                half2 uv = input.uv;
+                half4 texColor = SAMPLE_TEXTURE2D(_BaseMap, sampler_BaseMap, uv);
+                half3 color = texColor.rgb * _BaseColor.rgb;
+                half alpha = texColor.a * _BaseColor.a;
+                AlphaDiscard(alpha, _Cutoff);
+
+                half4 lightmapColor = SAMPLE_TEXTURE2D(_LightMap, sampler_LightMap, input.uv2);
+                color.rgb = color.rgb * lightmapColor.rgb * 2.0f;
+                //color.rgb = lightmapColor.rgb;
+
+#ifdef _ALPHAPREMULTIPLY_ON
+                color *= alpha;
+#endif
+
+                //color = MixFog(color, input.fogCoord);
+
+                return half4(color, alpha);
+            }
+            ENDHLSL
+        }
+        Pass
+        {
+            Name "DepthOnly"
+            Tags{"LightMode" = "DepthOnly"}
+
+            ZWrite On
+            ColorMask 0
+
+            HLSLPROGRAM
+            #pragma exclude_renderers gles gles3 glcore
+            #pragma target 4.5
+
+            #pragma vertex DepthOnlyVertex
+            #pragma fragment DepthOnlyFragment
+
+            // -------------------------------------
+            // Material Keywords
+            #pragma shader_feature_local_fragment _ALPHATEST_ON
+
+            //--------------------------------------
+            // GPU Instancing
+            #pragma multi_compile_instancing
+            #pragma multi_compile _ DOTS_INSTANCING_ON
+
+            #include "LightmappedInput.hlsl"
+            #include "Packages/com.unity.render-pipelines.universal/Shaders/DepthOnlyPass.hlsl"
+            ENDHLSL
+        }
+
+        // This pass it not used during regular rendering, only for lightmap baking.
+        Pass
+        {
+            Name "Meta"
+            Tags{"LightMode" = "Meta"}
+
+            Cull Off
+
+            HLSLPROGRAM
+            #pragma exclude_renderers gles gles3 glcore
+            #pragma target 4.5
+
+            #pragma vertex UniversalVertexMeta
+            #pragma fragment UniversalFragmentMetaUnlit
+
+            #include "LightmappedInput.hlsl"
+            #include "Packages/com.unity.render-pipelines.universal/Shaders/UnlitMetaPass.hlsl"
+
+            ENDHLSL
+        }
+    }
+
+    SubShader
+    {
+        Tags {"RenderType" = "Opaque" "IgnoreProjector" = "True" "RenderPipeline" = "UniversalPipeline" "ShaderModel"="2.0"}
+        LOD 100
+
+        Blend [_SrcBlend][_DstBlend]
+        ZWrite [_ZWrite]
+        Cull [_Cull]
+
+        Pass
+        {
+            Name "Lightmapped"
+            HLSLPROGRAM
+            #pragma only_renderers gles gles3 glcore d3d11
+            #pragma target 2.0
+
+            #pragma vertex vert
+            #pragma fragment frag
+            #pragma shader_feature_local_fragment _ALPHATEST_ON
+            #pragma shader_feature_local_fragment _ALPHAPREMULTIPLY_ON
+
+            // -------------------------------------
+            // Unity defined keywords
+            #pragma multi_compile_fog
+            #pragma multi_compile_instancing
+
+            #include "LightmappedInput.hlsl"
+
+            struct Attributes
+            {
+                float4 positionOS       : POSITION;
+                float2 uv               : TEXCOORD0;
+                UNITY_VERTEX_INPUT_INSTANCE_ID
+            };
+
+            struct Varyings
+            {
+                float2 uv        : TEXCOORD0;
+                float fogCoord  : TEXCOORD1;
+                float4 vertex : SV_POSITION;
+
+                UNITY_VERTEX_INPUT_INSTANCE_ID
+                UNITY_VERTEX_OUTPUT_STEREO
+            };
+
+            Varyings vert(Attributes input)
+            {
+                Varyings output = (Varyings)0;
+
+                UNITY_SETUP_INSTANCE_ID(input);
+                UNITY_TRANSFER_INSTANCE_ID(input, output);
+                UNITY_INITIALIZE_VERTEX_OUTPUT_STEREO(output);
+
+                VertexPositionInputs vertexInput = GetVertexPositionInputs(input.positionOS.xyz);
+                output.vertex = vertexInput.positionCS;
+                output.uv = TRANSFORM_TEX(input.uv, _BaseMap);
+                output.fogCoord = ComputeFogFactor(vertexInput.positionCS.z);
+
+                return output;
+            }
+
+            half4 frag(Varyings input) : SV_Target
+            {
+                UNITY_SETUP_INSTANCE_ID(input);
+                UNITY_SETUP_STEREO_EYE_INDEX_POST_VERTEX(input);
+
+                half2 uv = input.uv;
+                half4 texColor = SAMPLE_TEXTURE2D(_BaseMap, sampler_BaseMap, uv);
+                half3 color = texColor.rgb * _BaseColor.rgb;
+                half alpha = texColor.a * _BaseColor.a;
+                AlphaDiscard(alpha, _Cutoff);
+
+#ifdef _ALPHAPREMULTIPLY_ON
+                color *= alpha;
+#endif
+
+                color = MixFog(color, input.fogCoord);
+                alpha = OutputAlpha(alpha, _Surface);
+
+                return half4(color, alpha);
+            }
+            ENDHLSL
+        }
+        Pass
+        {
+            Name "DepthOnly"
+            Tags{"LightMode" = "DepthOnly"}
+
+            ZWrite On
+            ColorMask 0
+
+            HLSLPROGRAM
+            #pragma only_renderers gles gles3 glcore d3d11
+            #pragma target 2.0
+
+            #pragma vertex DepthOnlyVertex
+            #pragma fragment DepthOnlyFragment
+
+            // -------------------------------------
+            // Material Keywords
+            #pragma shader_feature_local_fragment _ALPHATEST_ON
+
+            //--------------------------------------
+            // GPU Instancing
+            #pragma multi_compile_instancing
+
+            #include "LightmappedInput.hlsl"
+            #include "Packages/com.unity.render-pipelines.universal/Shaders/DepthOnlyPass.hlsl"
+            ENDHLSL
+        }
+
+        // This pass it not used during regular rendering, only for lightmap baking.
+        Pass
+        {
+            Name "Meta"
+            Tags{"LightMode" = "Meta"}
+
+            Cull Off
+
+            HLSLPROGRAM
+            #pragma only_renderers gles gles3 glcore d3d11
+            #pragma target 2.0
+
+            #pragma vertex UniversalVertexMeta
+            #pragma fragment UniversalFragmentMetaUnlit
+
+            #include "LightmappedInput.hlsl"
+            #include "Packages/com.unity.render-pipelines.universal/Shaders/UnlitMetaPass.hlsl"
+
+            ENDHLSL
+        }
+    }
+    FallBack "Hidden/Universal Render Pipeline/FallbackError"
+    //CustomEditor "UnityEditor.Rendering.Universal.ShaderGUI.UnlitShader"
+}

Assets/Shaders/Lightmapped.shader.meta

@@ -0,0 +1,10 @@
+fileFormatVersion: 2
+guid: 91d80b5043d41db478595fab96d6e2c2
+ShaderImporter:
+  externalObjects: {}
+  defaultTextures: []
+  nonModifiableTextures: []
+  preprocessorOverride: 0
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Shaders/LightmappedInput.hlsl

@@ -0,0 +1,28 @@
+#ifndef UNIVERSAL_UNLIT_INPUT_INCLUDED
+#define UNIVERSAL_UNLIT_INPUT_INCLUDED
+
+#include "Packages/com.unity.render-pipelines.universal/ShaderLibrary/SurfaceInput.hlsl"
+
+TEXTURE2D(_LightMap);            SAMPLER(sampler_LightMap);
+
+CBUFFER_START(UnityPerMaterial)
+    float4 _BaseMap_ST;
+    float4 _LightMap_ST;
+    half4 _BaseColor;
+    half _Cutoff;
+    half _Surface;
+CBUFFER_END
+
+#ifdef UNITY_DOTS_INSTANCING_ENABLED
+UNITY_DOTS_INSTANCING_START(MaterialPropertyMetadata)
+    UNITY_DOTS_INSTANCED_PROP(float4, _BaseColor)
+    UNITY_DOTS_INSTANCED_PROP(float , _Cutoff)
+    UNITY_DOTS_INSTANCED_PROP(float , _Surface)
+UNITY_DOTS_INSTANCING_END(MaterialPropertyMetadata)
+
+#define _BaseColor          UNITY_ACCESS_DOTS_INSTANCED_PROP_FROM_MACRO(float4 , Metadata__BaseColor)
+#define _Cutoff             UNITY_ACCESS_DOTS_INSTANCED_PROP_FROM_MACRO(float  , Metadata__Cutoff)
+#define _Surface            UNITY_ACCESS_DOTS_INSTANCED_PROP_FROM_MACRO(float  , Metadata__Surface)
+#endif
+
+#endif

Assets/Shaders/LightmappedInput.hlsl.meta

@@ -0,0 +1,10 @@
+fileFormatVersion: 2
+guid: fe2f7d54113588c42925192dff3809e9
+ShaderImporter:
+  externalObjects: {}
+  defaultTextures: []
+  nonModifiableTextures: []
+  preprocessorOverride: 0
+  userData: 
+  assetBundleName: 
+  assetBundleVariant: 

Assets/Styles/GLQuake/Materials/GLQuake_World.mat

@@ -21,14 +21,13 @@ Material:
   m_PrefabInstance: {fileID: 0}
   m_PrefabAsset: {fileID: 0}
   m_Name: GLQuake_World
-  m_Shader: {fileID: 4800000, guid: 8d2bb70cbf9db8d4da26e15b26e74248, type: 3}
+  m_Shader: {fileID: 4800000, guid: 91d80b5043d41db478595fab96d6e2c2, type: 3}
   m_ShaderKeywords: _EMISSION _RECEIVE_SHADOWS_OFF
   m_LightmapFlags: 2
   m_EnableInstancingVariants: 0
   m_DoubleSidedGI: 0
-  m_CustomRenderQueue: 2000
-  stringTagMap:
-    RenderType: Opaque
+  m_CustomRenderQueue: -1
+  stringTagMap: {}
   disabledShaderPasses: []
   m_SavedProperties:
     serializedVersion: 3
@@ -61,6 +60,10 @@ Material:
         m_Texture: {fileID: 0}
         m_Scale: {x: 1, y: 1}
         m_Offset: {x: 0, y: 0}
+    - _LightMap:
+        m_Texture: {fileID: 0}
+        m_Scale: {x: 1, y: 1}
+        m_Offset: {x: 0, y: 0}
     - _MainTex:
         m_Texture: {fileID: 0}
         m_Scale: {x: 1, y: 1}

ProjectSettings/GraphicsSettings.asset

@@ -60,7 +60,7 @@ GraphicsSettings:
   m_FogKeepExp: 1
   m_FogKeepExp2: 1
   m_AlbedoSwatchInfos: []
-  m_LightsUseLinearIntensity: 1
+  m_LightsUseLinearIntensity: 0
   m_LightsUseColorTemperature: 0
   m_DefaultRenderingLayerMask: 1
   m_LogWhenShaderIsCompiled: 0

ProjectSettings/ProjectSettings.asset

@@ -47,7 +47,7 @@ PlayerSettings:
   defaultScreenWidthWeb: 960
   defaultScreenHeightWeb: 600
   m_StereoRenderingPath: 0
-  m_ActiveColorSpace: 1
+  m_ActiveColorSpace: 0
   m_MTRendering: 1
   mipStripping: 0
   numberOfMipsStripped: 0