[URP] Lit Shader Detail Fixes (#5432)

* Fixed lit detail correctly upgraded from standard shader. [1323725]

* Added warning for lit shader detailed abledo, if texture is not linear. [1342011]

* Updating changelog

* Adding missing namespace

* Updating changelog and extending comments

Author: lukaschod

com.unity.render-pipelines.universal/CHANGELOG.md

@@ -13,6 +13,8 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 - Removed experimental tile deferred code.
 
 ### Fixed
+- Added warning for lit shader detailed abledo, if texture is not linear. [1342011](https://issuetracker.unity3d.com/issues/detail-maps-packed-differently-in-built-in-vs-urp)
+- Fixed lit detail correctly upgraded from standard shader. [1323725](https://issuetracker.unity3d.com/issues/urp-detail-map-tiling-is-tied-to-base-texture-tiling)
 - URP asset can now use multi-edit. [case 1364966](https://issuetracker.unity3d.com/issues/urp-universalrenderpipelineasset-does-not-support-multi-edit)
 
 ## [12.0.0] - 2021-01-11

com.unity.render-pipelines.universal/Editor/ShaderGUI/ShadingModels/LitDetailGUI.cs

@@ -1,5 +1,6 @@
 using UnityEngine;
 using UnityEngine.Rendering;
+using UnityEngine.Experimental.Rendering;
 
 namespace UnityEditor.Rendering.Universal.ShaderGUI
 {
@@ -20,6 +21,7 @@ public static class Styles
                 "Designates a Normal Map to create the illusion of bumps and dents in the details of this Material's surface.");
 
             public static readonly GUIContent detailAlbedoMapScaleInfo = EditorGUIUtility.TrTextContent("Setting the scaling factor to a value other than 1 results in a less performant shader variant.");
+            public static readonly GUIContent detailAlbedoMapFormatError = EditorGUIUtility.TrTextContent("This texture is not in linear space.");
         }
 
         public struct LitProperties
@@ -49,6 +51,11 @@ public static void DoDetailArea(LitProperties properties, MaterialEditor materia
             {
                 EditorGUILayout.HelpBox(Styles.detailAlbedoMapScaleInfo.text, MessageType.Info, true);
             }
+            var detailAlbedoTexture = properties.detailAlbedoMap.textureValue as Texture2D;
+            if (detailAlbedoTexture != null && GraphicsFormatUtility.IsSRGBFormat(detailAlbedoTexture.graphicsFormat))
+            {
+                EditorGUILayout.HelpBox(Styles.detailAlbedoMapFormatError.text, MessageType.Warning, true);
+            }
             materialEditor.TexturePropertySingleLine(Styles.detailNormalMapText, properties.detailNormalMap,
                 properties.detailNormalMap.textureValue != null ? properties.detailNormalMapScale : null);
             materialEditor.TextureScaleOffsetProperty(properties.detailAlbedoMap);

com.unity.render-pipelines.universal/Editor/UniversalRenderPipelineMaterialUpgrader.cs

@@ -373,6 +373,7 @@ public static void UpdateStandardMaterialKeywords(Material material)
             CoreUtils.SetKeyword(material, "_OCCLUSIONMAP", material.GetTexture("_OcclusionMap"));
             CoreUtils.SetKeyword(material, "_METALLICSPECGLOSSMAP", material.GetTexture("_MetallicGlossMap"));
             UpdateSurfaceTypeAndBlendMode(material);
+            UpdateDetailScaleOffset(material);
             BaseShaderGUI.SetupMaterialBlendMode(material);
         }
 
@@ -391,9 +392,24 @@ public static void UpdateStandardSpecularMaterialKeywords(Material material)
             CoreUtils.SetKeyword(material, "_METALLICSPECGLOSSMAP", material.GetTexture("_SpecGlossMap"));
             CoreUtils.SetKeyword(material, "_SPECULAR_SETUP", true);
             UpdateSurfaceTypeAndBlendMode(material);
+            UpdateDetailScaleOffset(material);
             BaseShaderGUI.SetupMaterialBlendMode(material);
         }
 
+        static void UpdateDetailScaleOffset(Material material)
+        {
+            // In URP details tile/offset is multipied with base tile/offset, where in builtin is not
+            // Basically we setup new tile/offset values that in shader they would result in same values as in builtin
+            // This archieved with inverted calculation where scale=detailScale/baseScale and tile=detailOffset-baseOffset*scale
+            var baseScale = material.GetTextureScale("_BaseMap");
+            var baseOffset = material.GetTextureOffset("_BaseMap");
+            var detailScale = material.GetTextureScale("_DetailAlbedoMap");
+            var detailOffset = material.GetTextureOffset("_DetailAlbedoMap");
+            var scale = new Vector2(baseScale.x == 0 ? 0 : detailScale.x / baseScale.x, baseScale.y == 0 ? 0 : detailScale.y / baseScale.y);
+            material.SetTextureScale("_DetailAlbedoMap", scale);
+            material.SetTextureOffset("_DetailAlbedoMap", new Vector2((detailOffset.x - baseOffset.x * scale.x), (detailOffset.y - baseOffset.y * scale.y)));
+        }
+
         // Converts from legacy RenderingMode to new SurfaceType and BlendMode
         static void UpdateSurfaceTypeAndBlendMode(Material material)
         {