UE4.27 support

- Updated unversioned props tables
- Updated versions constants
- UnMesh4.cpp has removed hack with pre-enabled "KeepMobileMinLODSettingOnDesktop"
- Some code cleanup, added comments etc

Author: gildor2

Docs/UE4Props.pl

@@ -1,8 +1,16 @@
 #!/usr/bin/perl -w
 
+# TODO:
+# - command line (has some commented code here)
+# - show file/line where class defined
+# - command line: show particular class and its parents
+# - when there's parent, parse its prpos and add count to the 1st property (e.g. for UMaterialInstanceConstant)
+
+
 @dirs =
 (
-	"../../Epic/UnrealEngine4-latest/Engine/Source/Runtime/Engine",
+	"../../Epic/UnrealEngine4/Engine/Source/Runtime/Engine",
+#	"../../Epic/UnrealEngine4-latest/Engine/Source/Runtime/Engine",
 );
 
 @files =

Docs/UE4Version.pl

@@ -13,6 +13,7 @@
 	"EditorObjectVersion.h",
 	"../../../Engine/Public/SkeletalMeshTypes.h",	# for newer UE4 (post UE4.18)
 	"../../../Engine/Private/SkeletalMesh.cpp",		# for older UE4 version (UE4.18 and less)
+	"../../../Engine/Public/SkeletalMeshLegacyCustomVersions.h", # UE4.27 and newer
 	"CoreObjectVersion.h",
 	"RenderingObjectVersion.h",
 	"AnimObjectVersion.h",

Unreal/UE4Version.h

@@ -95,13 +95,30 @@ enum
 		VER_UE4_SKINWEIGHT_PROFILE_DATA_LAYOUT_CHANGES = 519,
 		VER_UE4_NON_OUTER_PACKAGE_IMPORT = 520,
 	VER_UE4_26 = 522,
-	VER_UE4_27 = 523, //?? TODO
+	VER_UE4_27 = 522,
 	// look for NEW_ENGINE_VERSION over the code to find places where version constants should be inserted.
 	// LATEST_SUPPORTED_UE4_VERSION should be updated too.
 };
 
 int GetUE4CustomVersion(const FArchive& Ar, const FGuid& Guid);
 
+
+/*
+ * Rules for writing code for custom versions
+ * - Each version is a "struct". Ideally could use "enum class", however we're adding some code into it, so "struct" is ideal.
+ * - Use "enum Type" inside of it.
+ * - Each enum has members:
+ *   - VersionPlusOne - equals to the recent declared constant + 1, used to correctly set up LatestVersion without explicit
+ *     mentioning of the latest constant name.
+ *   - optional: ForceVersion - use it in a case we're not declaring the latest version as a constant, so LatestVersion value
+ *     will work correctly.
+ * - There's "static Type Get(const FArchive& Ar)" function, it computes custom version based on Game constant. Needed in order
+ *   to make unversioned packages to work.
+ * - This function does comparison of game constant with engine number PLUS ONE, so games which are derived from e.g. UE4.25
+ *   will work correctly after using logic "Game < GAME_UE4(26)", i.e. game is using engine smaller than UE4.26. If we'll use
+ *   "Game <= GAME_UE4.25", this WILL work for UE4.25, but not for 4.25-based games which has custom override.
+ */
+
 struct FFrameworkObjectVersion
 {
 	enum Type
@@ -124,7 +141,9 @@ struct FFrameworkObjectVersion
 		// UE4.20, UE4.21 = 34
 		// UE4.22, UE4.23 = 35
 		// UE4.24 = 36
-		// UE4.25, UE4.26 = 37
+		// UE4.25-UE4.27 = 37
+
+		ForceVersion = 37, // the recent version, added here just to force LatestVersion to be correct
 
 		VersionPlusOne,
 		LatestVersion = VersionPlusOne - 1
@@ -165,10 +184,10 @@ struct FFrameworkObjectVersion
 			return (Type)35;
 		if (Ar.Game < GAME_UE4(25))
 			return (Type)36;
-//		if (Ar.Game < GAME_UE4(27))
+		if (Ar.Game < GAME_UE4(28))
 			return (Type)37;
 		// NEW_ENGINE_VERSION
-//		return LatestVersion;
+		return LatestVersion;
 	}
 };
 
@@ -195,7 +214,9 @@ struct FEditorObjectVersion
 		// UE4.23 = 34
 		// UE4.24 = 37
 		// UE4.25 = 38
-		// UE4.26 = 40
+		// UE4.26, UE4.27 = 40
+
+		ForceVersion = 40,
 
 		VersionPlusOne,
 		LatestVersion = VersionPlusOne - 1
@@ -243,10 +264,10 @@ struct FEditorObjectVersion
 			return (Type)37;
 		if (Ar.Game < GAME_UE4(26))
 			return (Type)38;
-//		if (Ar.Game < GAME_UE4(27))
+		if (Ar.Game < GAME_UE4(28))
 			return (Type)40;
 		// NEW_ENGINE_VERSION
-//		return LatestVersion;
+		return LatestVersion;
 	}
 };
 
@@ -278,7 +299,7 @@ struct FSkeletalMeshCustomVersion
 		SectionIgnoreByReduceAdded = 16,
 		// UE4.23-UE4.25 = 17
 		SkinWeightProfiles = 17, //todo: FSkeletalMeshLODModel::Serialize (editor mesh)
-		// UE4.26 = 18
+		// UE4.26, UE4.27 = 18
 		RemoveEnableClothLOD = 18, //todo
 
 		VersionPlusOne,
@@ -316,10 +337,10 @@ struct FSkeletalMeshCustomVersion
 			return SectionIgnoreByReduceAdded;
 		if (Ar.Game < GAME_UE4(26))
 			return SkinWeightProfiles;
-//		if (Ar.Game < GAME_UE4(27))
+		if (Ar.Game < GAME_UE4(28))
 			return RemoveEnableClothLOD;
 		// NEW_ENGINE_VERSION
-//		return LatestVersion;
+		return LatestVersion;
 	}
 };
 
@@ -333,7 +354,7 @@ struct FCoreObjectVersion
 		// UE4.15-UE4.21 = 2
 		// UE4.22-UE4.24 = 3
 		SkeletalMaterialEditorDataStripping = 3,
-		// UE4.25-UE4.26 = 4
+		// UE4.25-UE4.27 = 4
 
 		VersionPlusOne,
 		LatestVersion = VersionPlusOne - 1
@@ -353,10 +374,10 @@ struct FCoreObjectVersion
 			return (Type)2;
 		if (Ar.Game < GAME_UE4(25))
 			return SkeletalMaterialEditorDataStripping;
-//		if (Ar.Game < GAME_UE4(27))
+		if (Ar.Game < GAME_UE4(28))
 			return (Type)4;
 		// NEW_ENGINE_VERSION
-//		return LatestVersion;
+		return LatestVersion;
 	}
 };
 
@@ -378,9 +399,12 @@ struct FRenderingObjectVersion
 		// UE4.22 = 28
 		// UE4.23 = 31
 		// UE4.24 = 36
+		StaticMeshSectionForceOpaqueField = 37,
 		// UE4.25 = 43
 		// UE4.26 = 44
-		StaticMeshSectionForceOpaqueField = 37,
+		// UE4.27 = 45
+
+		ForceVersion = 45,
 
 		VersionPlusOne,
 		LatestVersion = VersionPlusOne - 1
@@ -425,10 +449,12 @@ struct FRenderingObjectVersion
 			return (Type)36;
 		if (Ar.Game < GAME_UE4(26))
 			return (Type)43;
-//		if (Ar.Game < GAME_UE4(27))
+		if (Ar.Game < GAME_UE4(27))
 			return (Type)44;
+		if (Ar.Game < GAME_UE4(28))
+			return (Type)45;
 		// NEW_ENGINE_VERSION
-//		return LatestVersion;
+		return LatestVersion;
 	}
 };
 
@@ -442,7 +468,9 @@ struct FAnimObjectVersion
 		// UE4.25 = 7
 		IncreaseBoneIndexLimitPerChunk = 4,
 		UnlimitedBoneInfluences = 5,
-		// UE4.26 = 15
+		// UE4.26, UE4.27 = 15
+
+		ForceVersion = 15,
 
 		VersionPlusOne,
 		LatestVersion = VersionPlusOne - 1
@@ -460,11 +488,10 @@ struct FAnimObjectVersion
 			return StoreMarkerNamesOnSkeleton;
 		if (Ar.Game < GAME_UE4(26))
 			return (Type)7;
-//		if (Ar.Game < GAME_UE4(27))
+		if (Ar.Game < GAME_UE4(28))
 			return (Type)15;
-
 		// NEW_ENGINE_VERSION
-//		return LatestVersion;
+		return LatestVersion;
 	}
 };
 
@@ -481,7 +508,9 @@ struct FAnimPhysObjectVersion
 		AddLODToCurveMetaData = 12,
 		// UE4.19 = 16
 		ChangeRetargetSourceReferenceToSoftObjectPtr = 15,
-		// UE4.20-UE4.26 = 17
+		// UE4.20-UE4.27 = 17
+
+		ForceVersion = 17,
 
 		VersionPlusOne,
 		LatestVersion = VersionPlusOne - 1
@@ -503,10 +532,10 @@ struct FAnimPhysObjectVersion
 			return AddLODToCurveMetaData;
 		if (Ar.Game < GAME_UE4(20))
 			return (Type)16;
-//		if (Ar.Game < GAME_UE4(27))
+		if (Ar.Game < GAME_UE4(28))
 			return (Type)17;
 		// NEW_ENGINE_VERSION
-//		return LatestVersion;
+		return LatestVersion;
 	}
 };
 
@@ -517,6 +546,9 @@ struct FReleaseObjectVersion
 		BeforeCustomVersionWasAdded = 0,
 		// UE4.19 = 12
 		AddSkeletalMeshSectionDisable = 12,
+		// Not used in our code, so for version mapping please refer to "Get()" method below...
+
+		ForceVersion = 43,
 
 		VersionPlusOne,
 		LatestVersion = VersionPlusOne - 1
@@ -554,10 +586,12 @@ struct FReleaseObjectVersion
 			return (Type)28;
 		if (Ar.Game < GAME_UE4(26))
 			return (Type)30;
-//		if (Ar.Game < GAME_UE4(27))
+		if (Ar.Game < GAME_UE4(27))
 			return (Type)37;
+		if (Ar.Game < GAME_UE4(28))
+			return (Type)43;
 		// NEW_ENGINE_VERSION
-//		return LatestVersion;
+		return LatestVersion;
 	}
 };
 
@@ -569,6 +603,8 @@ struct FEnterpriseObjectVersion
 		// UE4.24 = 8
 		MeshDescriptionBulkDataGuidIsHash = 8,
 
+		ForceVersion = 10,
+
 		VersionPlusOne,
 		LatestVersion = VersionPlusOne - 1
 	};
@@ -589,10 +625,10 @@ struct FEnterpriseObjectVersion
 			return (Type)6;
 		if (Ar.Game < GAME_UE4(25))
 			return MeshDescriptionBulkDataGuidIsHash;
-//		if (Ar.Game < GAME_UE4(27))
+		if (Ar.Game < GAME_UE4(28))
 			return (Type)10;
 		// NEW_ENGINE_VERSION
-//		return LatestVersion;
+		return LatestVersion;
 	}
 };
 

Unreal/UnObject4.cpp

@@ -85,7 +85,11 @@ struct PropInfo
 
 static const PropInfo PropData[] =
 {
+// UStaticMesh
 BEGIN("UStaticMesh4")
+	VERSION_BLOCK(GAME_UE4(27))
+		DROP_INT8(14)					// uint8 bSupportRayTracing
+	VERSION_BLOCK(0)
 	DROP_INT64(0)						// FPerPlatformInt MinLOD - serialized as 2x int32, didn't find why
 	MAP(StaticMaterials, 2)
 	MAP(LightmapUVDensity, 3)
@@ -97,7 +101,11 @@ BEGIN("UStaticMesh4")
 	DROP_OBJ_ARRAY(22)					// TArray<UAssetUserData*> AssetUserData
 END
 
+// USkeletalMesh
 BEGIN("USkeletalMesh4")
+	VERSION_BLOCK(GAME_UE4(27))
+		DROP_INT8(21)					// uint8 bSupportRayTracing
+	VERSION_BLOCK(0)
 	MAP(Skeleton, 0)
 	DROP_VECTOR3(3)						// PositiveBoundsExtension
 	DROP_VECTOR3(4)						// PositiveBoundsExtension
@@ -125,20 +133,23 @@ BEGIN("USkeleton")
 	DROP_OBJ_ARRAY(8)					// TArray<UAssetUserData*> AssetUserData
 END
 
+// UAnimSequence
 BEGIN("UAnimSequence4")
+	VERSION_BLOCK(GAME_UE4(27))
+		MAP(RetargetSourceAssetReferencePose, 9)
+	VERSION_BLOCK(0)
 	MAP(NumFrames, 0)
 	MAP(TrackToSkeletonMapTable, 1)
 	MAP(AdditiveAnimType, 4)
 	MAP(RefPoseType, 5)
 	MAP(RefPoseSeq, 6)
 	MAP(RefFrameIndex, 7)
 	MAP(RetargetSource, 8)
-	MAP(RetargetSourceAssetReferencePose, 9)
-	MAP(Interpolation, 10)
-	MAP(bEnableRootMotion, 11)
-	DROP_INT8(12, 13, 14, 15)
-	MAP(AuthoredSyncMarkers, 16)
-	MAP(BakedPerBoneCustomAttributeData, 17)
+	MAP(Interpolation, 9)
+	MAP(bEnableRootMotion, 10)
+	DROP_INT8(11, 12, 13, 14)
+	MAP(AuthoredSyncMarkers, 15)
+	MAP(BakedPerBoneCustomAttributeData, 16)
 END
 
 BEGIN("UAnimationAsset")
@@ -147,6 +158,7 @@ BEGIN("UAnimationAsset")
 	DROP_OBJ_ARRAY(2)					// AssetUserData
 END
 
+// UTexture2D
 BEGIN("UTexture2D")
 	DROP_INT8(2)						// uint8 bTemporarilyDisableStreaming:1
 	DROP_INT8(3)						// TEnumAsByte<enum TextureAddress> AddressX
@@ -161,6 +173,7 @@ BEGIN("UTexture3")
 	DROP_OBJ_ARRAY(14)					// AssetUserData
 END
 
+// UMaterialInstance
 BEGIN("UMaterialInstance")
 	MAP(Parent, 9)
 	DROP_INT8(10, 11)
@@ -174,6 +187,7 @@ BEGIN("UMaterialInstance")
 	DROP_OBJ_ARRAY(20)					//todo: TArray<UObject*> CachedReferencedTextures
 END
 
+// UMaterial
 BEGIN("UMaterial3")
 	// known properties
 	MAP(BlendMode, 17)
@@ -278,13 +292,18 @@ static const ParentInfo ParentData[] =
 	{ "UTexture2D", "UTexture3", 6 },
 	{ "UTexture3", "UStreamableRenderAsset", 15 },
 	// Mesh classes
+	{ "USkeletalMesh4", "UStreamableRenderAsset", 29, GAME_UE4(27) },
 	{ "USkeletalMesh4", "UStreamableRenderAsset", 28 },
+	{ "UStaticMesh4", "UStreamableRenderAsset", 26, GAME_UE4(27) },
 	{ "UStaticMesh4", "UStreamableRenderAsset", 25 },
 	// Material classes
 	{ "UMaterialInstanceConstant", "UMaterialInstance", 1 }, // contains just a single UObject* property
 	{ "UMaterialInstance", "UMaterialInterface", 21 },
+	{ "UMaterial3", "UMaterialInterface", 119, GAME_UE4(27) },
 	{ "UMaterial3", "UMaterialInterface", 117 },
-	{ "UAnimSequence4", "UAnimSequenceBase", 18 },
+	// Animation classes
+	{ "UAnimSequence4", "UAnimSequenceBase", 18, GAME_UE4(27) },
+	{ "UAnimSequence4", "UAnimSequenceBase", 17 },
 	{ "UAnimSequenceBase", "UAnimationAsset", 4 },
 	// Structures
 	{ "FStaticSwitchParameter", "FStaticParameterBase", 1 },

Unreal/UnrealMesh/UnMesh4.cpp

@@ -53,6 +53,8 @@
 #error MAX_STATIC_UV_SETS_UE4 too large
 #endif
 
+// This is a CVar in UE4.27+. Set to false by default, some games might have it set to "true".
+static bool KeepMobileMinLODSettingOnDesktop = false;
 
 /*-----------------------------------------------------------------------------
 	Common data types
@@ -1831,7 +1833,7 @@ void USkeletalMesh4::Serialize(FArchive &Ar)
 		bool bCooked;
 		Ar << bCooked;
 
-		if (Ar.Game >= GAME_UE4(27))
+		if (Ar.Game >= GAME_UE4(27) && KeepMobileMinLODSettingOnDesktop)
 		{
 			// The serialization of this variable is cvar-dependent in UE4, so there's no clear way to understand
 			// if it should be serialize in our code or not.
@@ -2728,7 +2730,7 @@ void UStaticMesh4::Serialize(FArchive &Ar)
 		// Note: code below still contains 'if (bCooked)' switches, this is because the same
 		// code could be used to read data from DDC, for non-cooked assets.
 		DBG_STAT("Serializing RenderData\n");
-		if (Ar.Game >= GAME_UE4(27))
+		if (Ar.Game >= GAME_UE4(27) && KeepMobileMinLODSettingOnDesktop)
 		{
 			// The serialization of this variable is cvar-dependent in UE4, so there's no clear way to understand
 			// if it should be serialize in our code or not.