diff --git a/source/core/defparser.cpp b/source/core/defparser.cpp
index 9b9e5bca4..262fc1176 100644
--- a/source/core/defparser.cpp
+++ b/source/core/defparser.cpp
@@ -83,6 +83,109 @@ void parseIncludeDefault(FScanner& sc, FScriptPosition& pos)
 	performInclude(&sc, G_DefaultDefFile(), &pos);
 }
 
+//===========================================================================
+// 
+//	Helpers for tile parsing
+//
+//===========================================================================
+
+bool ValidateTileRange(const char* cmd, int& begin, int& end, FScriptPosition pos, bool allowswap = true)
+{
+	if (end < begin)
+	{
+		pos.Message(MSG_WARNING, "%s: tile range [%d..%d] is backwards. Indices were swapped.", cmd, begin, end);
+		std::swap(begin, end);
+	}
+
+	if ((unsigned)begin >= MAXUSERTILES || (unsigned)end >= MAXUSERTILES)
+	{
+		pos.Message(MSG_ERROR, "%s: Invalid tile range [%d..%d]", cmd, begin, end);
+		return false;
+	}
+
+	return true;
+}
+
+bool ValidateTilenum(const char* cmd, int tile, FScriptPosition pos)
+{
+	if ((unsigned)tile >= MAXUSERTILES)
+	{
+		pos.Message(MSG_ERROR, "%s: Invalid tile number %d", cmd, tile);
+		return false;
+	}
+
+	return true;
+}
+
+//===========================================================================
+// 
+//	Internal worker for tileImportTexture
+//
+//===========================================================================
+
+void processTileImport(const char* cmd, FScriptPosition& pos, TileImport& imp)
+{
+	if (!ValidateTilenum(cmd, imp.tile, pos))
+		return;
+
+	if (imp.crc32 != INT64_MAX && int(imp.crc32) != tileGetCRC32(imp.tile))
+		return;
+
+	if (imp.sizex != INT_MAX && tileWidth(imp.tile) != imp.sizex && tileHeight(imp.tile) != imp.sizey)
+		return;
+
+	imp.alphacut = clamp(imp.alphacut, 0, 255);
+
+	gi->SetTileProps(imp.tile, imp.surface, imp.vox, imp.shade);
+
+	if (imp.fn.IsNotEmpty() && tileImportFromTexture(imp.fn, imp.tile, imp.alphacut, imp.istexture) < 0) return;
+
+	TileFiles.tiledata[imp.tile].picanm.sf |= imp.flags;
+	// This is not quite the same as originally, for two reasons:
+	// 1: Since these are texture properties now, there's no need to clear them.
+	// 2: The original code assumed that an imported texture cannot have an offset. But this can import Doom patches and PNGs with grAb, so the situation is very different.
+	if (imp.xoffset == INT_MAX) imp.xoffset = tileLeftOffset(imp.tile);
+	else imp.xoffset = clamp(imp.xoffset, -128, 127);
+	if (imp.yoffset == INT_MAX) imp.yoffset = tileTopOffset(imp.tile);
+	else imp.yoffset = clamp(imp.yoffset, -128, 127);
+
+	auto tex = tileGetTexture(imp.tile);
+	if (tex)
+	{
+		tex->SetOffsets(imp.xoffset, imp.yoffset);
+		if (imp.flags & PICANM_NOFULLBRIGHT_BIT)
+		{
+			tex->SetDisableBrightmap();
+		}
+	}
+	if (imp.extra != INT_MAX) TileFiles.tiledata[imp.tile].picanm.extra = imp.extra;
+}
+
+//===========================================================================
+// 
+//	Internal worker for tileSetAnim
+//
+//===========================================================================
+
+void processSetAnim(const char* cmd, FScriptPosition& pos, SetAnim& imp)
+{
+	if (!ValidateTilenum(cmd, imp.tile1, pos) ||
+		!ValidateTilenum(cmd, imp.tile2, pos))
+		return;
+
+	if (imp.type < 0 || imp.type > 3)
+	{
+		pos.Message(MSG_ERROR, "%s: animation type must be 0-3, got %d", cmd, imp.type);
+		return;
+	}
+
+	int count = imp.tile2 - imp.tile1;
+	if (imp.type == (PICANM_ANIMTYPE_BACK >> PICANM_ANIMTYPE_SHIFT) && imp.tile1 > imp.tile2)
+		count = -count;
+
+	TileFiles.setAnim(imp.tile1, imp.type, imp.speed, count);
+}
+
 //===========================================================================
 //
 //
diff --git a/source/core/gamecontrol.cpp b/source/core/gamecontrol.cpp
index 773fec5e3..9b978c047 100644
--- a/source/core/gamecontrol.cpp
+++ b/source/core/gamecontrol.cpp
@@ -964,6 +964,7 @@ static void InitTextures()
 	gi->LoadGameTextures(); // loads game-side data that must be present before processing the .def files.
 	LoadDefinitions();
 	InitFont();				// InitFonts may only be called once all texture data has been initialized.
+	gi->SetupSpecialTextures();	// For installing dynamic or deleted textures in the texture manager. This must be done after parsing .def and before setting the aliases.
 	TileFiles.SetAliases();
 
 	lookups.postLoadTables();
@@ -972,7 +973,6 @@ static void InitTextures()
 	SetupFontSubstitution();
 	V_LoadTranslations();   // loading the translations must be delayed until the palettes have been fully set up.
 	UpdateUpscaleMask();
-	TileFiles.SetBackup();
 }
 
 //==========================================================================
diff --git a/source/core/gamestruct.h b/source/core/gamestruct.h
index b22f74524..76786550f 100644
--- a/source/core/gamestruct.h
+++ b/source/core/gamestruct.h
@@ -72,6 +72,7 @@ struct GameInterface
 	virtual bool GenerateSavePic() { return false; }
 	virtual void app_init() = 0;
 	virtual void LoadGameTextures() {}
+	virtual void SetupSpecialTextures() {}
 	virtual void loadPalette();
 	virtual void clearlocalinputstate() {}
 	virtual void UpdateScreenSize() {}
diff --git a/source/core/mainloop.cpp b/source/core/mainloop.cpp
index 419a2e20b..f511f4e5f 100644
--- a/source/core/mainloop.cpp
+++ b/source/core/mainloop.cpp
@@ -347,7 +347,6 @@ static void GameTicker()
 	{
 	default:
 	case GS_STARTUP:
-		artClearMapArt();
 		gi->Startup();
 		break;
 
diff --git a/source/core/maploader.cpp b/source/core/maploader.cpp
index e49dc2cbd..bf3b7ad2a 100644
--- a/source/core/maploader.cpp
+++ b/source/core/maploader.cpp
@@ -533,8 +533,6 @@ void loadMap(const char* filename, int flags, DVector3* pos, int16_t* ang, secto
 
 	}
 
-	artSetupMapArt(filename);
-
 	//Must be last.
 	fixSectors();
 	*cursect = validSectorIndex(cursectnum) ? &sector[cursectnum] : nullptr;
diff --git a/source/core/textures/buildtiles.cpp b/source/core/textures/buildtiles.cpp
index ddfc7e288..a1be4bbb5 100644
--- a/source/core/textures/buildtiles.cpp
+++ b/source/core/textures/buildtiles.cpp
@@ -142,7 +142,6 @@ void BuildTiles::Init()
 	for (auto& tile : tiledata)
 	{
 		tile.texture = Placeholder;
-		tile.backup = Placeholder;
 		tile.picanm = {};
 		tile.RotTile = { -1,-1 };
 		tile.replacement = ReplacementType::Art;
@@ -157,12 +156,11 @@ void BuildTiles::Init()
 //
 //==========================================================================
 
-void BuildTiles::AddTile(int tilenum, FGameTexture* tex, bool permap)
+void BuildTiles::AddTile(int tilenum, FGameTexture* tex)
 {
 	if (!tex->GetID().isValid())
 		TexMan.AddGameTexture(tex);
 	tiledata[tilenum].texture = tex;
-	if (!permap) tiledata[tilenum].backup = tex;
 }
 
 //===========================================================================
@@ -207,7 +205,7 @@ void BuildTiles::AddTiles (int firsttile, TArray<uint8_t>& RawData, const char *
 		auto tex = GetTileTexture(texname, RawData, uint32_t(tiledata - tiles), width, height);
 		AddTile(i, tex);
 		int leftoffset, topoffset;
-		this->tiledata[i].picanmbackup = this->tiledata[i].picanm = tileConvertAnimFormat(anm, &leftoffset, &topoffset);
+		this->tiledata[i].picanm = tileConvertAnimFormat(anm, &leftoffset, &topoffset);
 		tex->SetOffsets(leftoffset, topoffset);
 
 		tiledata += size;
@@ -372,9 +370,9 @@ void BuildTiles::SetAliases()
 
 FGameTexture* BuildTiles::ValidateCustomTile(int tilenum, ReplacementType type)
 {
+	if (locked) I_FatalError("Modifying tiles after startup is not allowed.");
 	if (tilenum < 0 || tilenum >= MAXTILES) return nullptr;
 	auto &td = tiledata[tilenum];
-	if (td.texture != td.backup) return nullptr;	// no mucking around with map tiles.
 	auto tile = td.texture;
 	auto reptype = td.replacement;
 	if (reptype == type) return tile;		// already created
@@ -391,11 +389,10 @@ FGameTexture* BuildTiles::ValidateCustomTile(int tilenum, ReplacementType type)
 	else if (type == ReplacementType::Restorable)
 	{
 		// This is for modifying an existing tile.
-		// It only gets used for the crosshair and a few specific effects:
+		// It only gets used for a few specific effects:
 		// A) the fire in Blood.
 		// B) the pin display in Redneck Rampage's bowling lanes.
 		// C) Exhumed's menu plus one special effect tile.
-		// All of these effects should probably be redone without actual texture hacking...
 		if (tile->GetTexelWidth() == 0 || tile->GetTexelHeight() == 0) return nullptr;	// The base must have a size for this to work.
 		// todo: invalidate hardware textures for tile.
 		replacement = new FImageTexture(new FRestorableTile(tile->GetTexture()->GetImage()));
@@ -437,6 +434,27 @@ int32_t BuildTiles::artLoadFiles(const char* filename)
 	return 0;
 }
 
+//==========================================================================
+//
+// Retrieves the pixel store for a modifiable tile
+// Modifiable tiles must be declared on startup.
+//
+//==========================================================================
+
+uint8_t* BuildTiles::tileGet(int tilenum)
+{
+	if (tilenum < 0 || tilenum >= MAXTILES) return nullptr;
+	auto& td = tiledata[tilenum];
+	auto tile = td.texture;
+	auto reptype = td.replacement;
+	if (reptype == ReplacementType::Writable || reptype == ReplacementType::Restorable)
+	{
+		auto wtex = static_cast<FWritableTile*>(tile->GetTexture()->GetImage());
+		if (wtex) return wtex->GetRawData();
+	}
+	return nullptr;
+}
+
 //==========================================================================
 //
 // Creates a tile for displaying custom content
@@ -537,7 +555,7 @@ int tileImportFromTexture(const char* fn, int tilenum, int alphacut, int istextu
 	// create a new game texture here - we want to give it a different name!
 	tex = MakeGameTexture(tex->GetTexture(), FStringf("#%05d", tilenum), ETextureType::Override);
 	TexMan.AddGameTexture(tex);
-	TileFiles.tiledata[tilenum].backup = TileFiles.tiledata[tilenum].texture = tex;
+	TileFiles.tiledata[tilenum].texture = tex;
 	if (istexture)
 		tileSetHightileReplacement(tilenum, 0, fn, (float)(255 - alphacut) * (1.f / 255.f), 1.0f, 1.0f, 1.0, 1.0);
 	return 0;
@@ -597,73 +615,6 @@ void tileCopy(int tile, int source, int pal, int xoffset, int yoffset, int flags
 	picanm->sf = (picanm->sf & ~PICANM_MISC_MASK) | (sourceanm->sf & PICANM_MISC_MASK) | flags;
 }
 
-//==========================================================================
-//
-// Clear map specific ART
-//
-//==========================================================================
-static FString currentMapArt;
-
-void artClearMapArt(void)
-{
-	for (auto& td : TileFiles.tiledata)
-	{
-		td.texture = td.backup;
-		td.picanm = td.picanmbackup;
-	}
-	currentMapArt = "";
-}
-
-//==========================================================================
-//
-// Load map specficied ART
-//
-//==========================================================================
-
-void artSetupMapArt(const char* filename)
-{
-	FString lcfilename = StripExtension(filename);
-	lcfilename.MakeLower();
-
-	if (currentMapArt.CompareNoCase(lcfilename) == 0) return;
-	artClearMapArt();
-	currentMapArt = lcfilename;
-
-
-	// Re-get from the texture manager if this map's tiles have already been created.
-	if (TileFiles.maptilesadded.Find(lcfilename) < TileFiles.maptilesadded.Size())
-	{
-		for (int i = 0; i < MAXTILES; i++)
-		{
-			FStringf name("maptile_%s_%05d", lcfilename.GetChars(), i);
-			auto texid = TexMan.CheckForTexture(name, ETextureType::Any);
-			if (texid.isValid())
-			{
-				TileFiles.tiledata[i].texture = TexMan.GetGameTexture(texid);
-			}
-		}
-		return;
-	}
-
-	TileFiles.maptilesadded.Push(lcfilename);
-
-
-	FStringf firstname("%s_00.art", lcfilename.GetChars());
-	auto fr = fileSystem.OpenFileReader(firstname);
-	if (!fr.isOpen()) return;
-	for (auto& td : TileFiles.tiledata)
-	{
-		td.picanmbackup = td.picanm;
-	}
-
-
-	for (int i = 0; i < MAXARTFILES_TOTAL - MAXARTFILES_BASE; i++)
-	{
-		FStringf fullname("%s_%02d.art", lcfilename.GetChars(), i);
-		TileFiles.LoadArtFile(fullname, filename);
-	}
-}
-
 //==========================================================================
 //
 //
@@ -672,7 +623,7 @@ void artSetupMapArt(const char* filename)
 
 void tileDelete(int tile)
 {
-	TileFiles.tiledata[tile].texture = TileFiles.tiledata[tile].backup = TexMan.GameByIndex(0);
+	TileFiles.tiledata[tile].texture = TexMan.GameByIndex(0);
 	TileFiles.tiledata[tile].replacement = ReplacementType::Art; // whatever this was, now it isn't anymore. (SW tries to nuke camera textures with this, :( )
 	tiletovox[tile] = -1; // clear the link but don't clear the voxel. It may be in use for another tile.
 	modelManager.UndefineTile(tile);
@@ -749,8 +700,7 @@ int BuildTiles::tileCreateRotated(int tileNum)
 
 	auto dtex = MakeGameTexture(new FImageTexture(new FLooseTile(dbuffer, tex->GetTexelHeight(), tex->GetTexelWidth())), "", ETextureType::Override);
 	int index = findUnusedTile();
-	bool mapart = TileFiles.tiledata[tileNum].texture != TileFiles.tiledata[tileNum].backup;
-	TileFiles.AddTile(index, dtex, mapart);
+	TileFiles.AddTile(index, dtex);
 	return index;
 }
 
@@ -846,30 +796,6 @@ int tileAnimateOfs(int tilenum, int randomize)
 	return 0;
 }
 
-//==========================================================================
-//
-//  Check if two tiles are the same
-//
-//==========================================================================
-
-bool tileEqualTo(int me, int other)
-{
-	auto tile = tileGetTexture(me);
-	auto tile2 = tileGetTexture(other);
-	int tilew1 = tile->GetTexelWidth();
-	int tileh1 = tile->GetTexelHeight();
-	int tilew2 = tile2->GetTexelWidth();
-	int tileh2 = tile2->GetTexelHeight();
-	if (tilew1 == tilew2 && tileh1 == tileh2)
-	{
-		auto p1 = tileRawData(me);
-		auto p2 = tileRawData(other);
-		if (p1 && p2 && !memcmp(p1, p2, tilew1 * tileh2))
-			return true;
-	}
-	return false;
-}
-
 //===========================================================================
 // 
 //	Picks a texture for rendering for a given tilenum/palette combination
@@ -909,136 +835,5 @@ FCanvasTexture* tileGetCanvas(int tilenum)
 	return canvas;
 }
 
-
-
-//===========================================================================
-// 
-//	Parsing stuff for tile data comes below.
-//
-//===========================================================================
-
-//===========================================================================
-// 
-//	Helpers for tile parsing
-//
-//===========================================================================
-
-bool ValidateTileRange(const char* cmd, int &begin, int& end, FScriptPosition pos, bool allowswap)
-{
-	if (end < begin)
-	{
-		pos.Message(MSG_WARNING, "%s: tile range [%d..%d] is backwards. Indices were swapped.", cmd, begin, end);
-		std::swap(begin, end);
-	}
-
-	if ((unsigned)begin >= MAXUSERTILES || (unsigned)end >= MAXUSERTILES)
-	{
-		pos.Message(MSG_ERROR, "%s: Invalid tile range [%d..%d]", cmd, begin, end);
-		return false;
-	}
-
-	return true;
-}
-
-bool ValidateTilenum(const char* cmd, int tile, FScriptPosition pos)
-{
-	if ((unsigned)tile >= MAXUSERTILES)
-	{
-		pos.Message(MSG_ERROR, "%s: Invalid tile number %d", cmd, tile);
-		return false;
-	}
-
-	return true;
-}
-
-//===========================================================================
-// 
-//	Internal worker for tileImportTexture
-//
-//===========================================================================
-
-void processTileImport(const char *cmd, FScriptPosition& pos, TileImport& imp)
-{
-	if (!ValidateTilenum(cmd, imp.tile, pos))
-		return;
-
-	if (imp.crc32 != INT64_MAX && int(imp.crc32) != tileGetCRC32(imp.tile))
-		return;
-
-	if (imp.sizex != INT_MAX && tileWidth(imp.tile) != imp.sizex && tileHeight(imp.tile) != imp.sizey)
-		return;
-
-	imp.alphacut = clamp(imp.alphacut, 0, 255);
-
-	gi->SetTileProps(imp.tile, imp.surface, imp.vox, imp.shade);
-
-	if (imp.fn.IsNotEmpty() && tileImportFromTexture(imp.fn, imp.tile, imp.alphacut, imp.istexture) < 0) return;
-
-	TileFiles.tiledata[imp.tile].picanm.sf |= imp.flags;
-	// This is not quite the same as originally, for two reasons:
-	// 1: Since these are texture properties now, there's no need to clear them.
-	// 2: The original code assumed that an imported texture cannot have an offset. But this can import Doom patches and PNGs with grAb, so the situation is very different.
-	if (imp.xoffset == INT_MAX) imp.xoffset = tileLeftOffset(imp.tile);
-	else imp.xoffset = clamp(imp.xoffset, -128, 127);
-	if (imp.yoffset == INT_MAX) imp.yoffset = tileTopOffset(imp.tile);
-	else imp.yoffset = clamp(imp.yoffset, -128, 127);
-
-	auto tex = tileGetTexture(imp.tile);
-	if (tex)
-	{
-		tex->SetOffsets(imp.xoffset, imp.yoffset);
-		if (imp.flags & PICANM_NOFULLBRIGHT_BIT)
-		{
-			tex->SetDisableBrightmap();
-		}
-	}
-	if (imp.extra != INT_MAX) TileFiles.tiledata[imp.tile].picanm.extra = imp.extra;
-}
-
-//===========================================================================
-// 
-//	Internal worker for tileSetAnim
-//
-//===========================================================================
-
-void processSetAnim(const char* cmd, FScriptPosition& pos, SetAnim& imp) 
-{
-	if (!ValidateTilenum(cmd, imp.tile1, pos) ||
-	    !ValidateTilenum(cmd, imp.tile2, pos))
-		return;
-
-	if (imp.type < 0 || imp.type > 3)
-	{
-		pos.Message(MSG_ERROR, "%s: animation type must be 0-3, got %d", cmd, imp.type);
-		return;
-	}
-
-	int count = imp.tile2 - imp.tile1;
-	if (imp.type == (PICANM_ANIMTYPE_BACK >> PICANM_ANIMTYPE_SHIFT) && imp.tile1 > imp.tile2)
-		count = -count;
-
-	TileFiles.setAnim(imp.tile1, imp.type, imp.speed, count);
-}
-
 PicAnm picanm;
 
-#if 0 // this only gets in if unavoidable. It'd be preferable if the script side can solely operate on texture names.
-#include "vm.h"
-
-static int GetTexture(int tile, int anim)
-{
-	if (tile < 0 || tile >= MAXTILES) return 0;
-	auto tex = tileGetTexture(tile, anim);
-	return tex ? tex->GetID().GetIndex() : 0;
-}
-
-DEFINE_ACTION_FUNCTION_NATIVE(_TileFiles, GetTexture, GetTexture)
-{
-	PARAM_PROLOGUE;
-	PARAM_INT(tile);
-	PARAM_BOOL(animate);
-	ACTION_RETURN_INT(GetTexture(tile, animate));
-}
-#endif
-
-
diff --git a/source/core/textures/buildtiles.h b/source/core/textures/buildtiles.h
index 84e4842da..e73b0ddb8 100644
--- a/source/core/textures/buildtiles.h
+++ b/source/core/textures/buildtiles.h
@@ -276,10 +276,8 @@ struct TileOffs
 struct TileDesc
 {
 	FGameTexture* texture;	// the currently active tile
-	FGameTexture* backup;	// original backup for map tiles
 	RawCacheNode rawCache;	// this is needed for hitscan testing to avoid reloading the texture each time.
 	picanm_t picanm;		// animation descriptor
-	picanm_t picanmbackup;	// animation descriptor backup when using map tiles
 	rottile_t RotTile;// = { -1,-1 };
 	ReplacementType replacement;
 	float alphaThreshold;
@@ -308,12 +306,18 @@ struct BuildTiles
 	TArray<FString> maptilesadded;
 	TMap<int, FGameTexture*> cameratextures;
 	TMap<FName, int> nametoindex;
+	bool locked;	// if this is true, no more tile modifications are allowed.
 
 	void addName(const char* name, int index)
 	{
 		nametoindex.Insert(name, index);
 	}
 
+	void lock()
+	{
+		locked = true;
+	}
+
 	int tileForName(const char* name)
 	{
 		FName nm(name, true);
@@ -332,22 +336,13 @@ struct BuildTiles
 		CloseAll();
 	}
 
-	void SetBackup()
-	{
-		for (auto& td : tiledata)
-		{
-			td.backup = td.texture;
-			td.picanmbackup = td.picanm;
-		}
-	}
-
 	void CloseAll();
 
-	void AddTile(int tilenum, FGameTexture* tex, bool permap = false);
+	void AddTile(int tilenum, FGameTexture* tex);
 
 	void AddTiles(int firsttile, TArray<uint8_t>& store, const char* mapname);
 
-	void AddFile(BuildArtFile* bfd, bool permap)
+	void AddFile(BuildArtFile* bfd)
 	{
 		ArtFiles.Push(bfd);
 	}
@@ -374,6 +369,7 @@ struct BuildTiles
 	int32_t artLoadFiles(const char* filename);
 	uint8_t* tileMakeWritable(int num);
 	uint8_t* tileCreate(int tilenum, int width, int height);
+	uint8_t* tileGet(int tilenum);
 	int findUnusedTile(void);
 	int tileCreateRotated(int owner);
 	void InvalidateTile(int num);
@@ -386,8 +382,6 @@ void tileCopy(int tile, int tempsource, int temppal, int xoffset, int yoffset, i
 void tileSetDummy(int tile, int width, int height);
 void tileDelete(int tile);
 bool tileLoad(int tileNum);
-void    artClearMapArt(void);
-void    artSetupMapArt(const char* filename);
 void tileCopySection(int tilenum1, int sx1, int sy1, int xsiz, int ysiz, int tilenum2, int sx2, int sy2);
 
 extern BuildTiles TileFiles;
@@ -422,14 +416,6 @@ inline uint8_t* tileData(int num)
 	return p ? p->GetRawData() : nullptr;
 }
 
-inline const uint8_t* tileRawData(int num)
-{
-	auto tex = dynamic_cast<FImageTexture*>(TileFiles.tiledata[num].texture->GetTexture());
-	if (!tex) return nullptr;
-	auto p = dynamic_cast<FTileTexture*>(tex->GetImage());
-	return p ? p->GetRawData() : nullptr;
-}
-
 // Some hacks to allow accessing the no longer existing arrays as if they still were arrays to avoid changing hundreds of lines of code.
 struct PicAnm
 {
@@ -498,13 +484,8 @@ inline FGameTexture* tileGetTexture(int tile, bool animate = false)
 	return TileFiles.tiledata[tile].texture;
 }
 
-bool tileEqualTo(int me, int other);
 void tileUpdateAnimations();
 
-bool ValidateTileRange(const char* cmd, int& begin, int& end, FScriptPosition pos, bool allowswap = true);
-bool ValidateTilenum(const char* cmd, int tile, FScriptPosition pos);
-
-
 struct TileImport
 {
 	FString fn;
@@ -520,14 +501,11 @@ struct TileImport
 
 };
 
-void processTileImport(const char* cmd, FScriptPosition& pos, TileImport& imp);
-
 struct SetAnim
 {
 	int tile1, tile2, speed, type;
 };
 
-void processSetAnim(const char* cmd, FScriptPosition& pos, SetAnim& imp);
 class FGameTexture;
 bool PickTexture(FGameTexture* tex, int paletteid, TexturePick& pick, bool wantindexed = false);
 FCanvasTexture* tileGetCanvas(int tilenum);
diff --git a/source/games/blood/src/actor.cpp b/source/games/blood/src/actor.cpp
index 81a156ffb..c5c9643a9 100644
--- a/source/games/blood/src/actor.cpp
+++ b/source/games/blood/src/actor.cpp
@@ -4889,14 +4889,6 @@ void MoveDude(DBloodActor* actor)
 			playerCorrectInertia(pPlayer, oldpos);
 		switch (nLink)
 		{
-		case kMarkerLowStack:
-			if (pPlayer && pPlayer->nPlayer == gViewIndex)
-				gotpic.Set(actor->sector()->floorpicnum);
-			break;
-		case kMarkerUpStack:
-			if (pPlayer && pPlayer->nPlayer == gViewIndex)
-				gotpic.Set(actor->sector()->ceilingpicnum);
-			break;
 		case kMarkerLowWater:
 		case kMarkerLowGoo:
 			actor->xspr.medium = kMediumNormal;
diff --git a/source/games/blood/src/blood.h b/source/games/blood/src/blood.h
index 594f7ba10..23bf7a935 100644
--- a/source/games/blood/src/blood.h
+++ b/source/games/blood/src/blood.h
@@ -143,6 +143,7 @@ struct GameInterface : public ::GameInterface
 	void EnterPortal(DCoreActor* viewer, int type) override;
 	void LeavePortal(DCoreActor* viewer, int type) override;
 	void LoadGameTextures() override;
+	void SetupSpecialTextures() override;
 	int GetCurrentSkill() override;
 	bool IsQAVInterpTypeValid(const FString& type) override;
 	void AddQAVInterpProps(const int res_id, const FString& interptype, const bool loopable, const TMap<int, TArray<int>>&& ignoredata) override;
diff --git a/source/games/blood/src/db.cpp b/source/games/blood/src/db.cpp
index 1d8df2475..18f1d88b4 100644
--- a/source/games/blood/src/db.cpp
+++ b/source/games/blood/src/db.cpp
@@ -267,9 +267,9 @@ void dbLoadMap(const char* pPath, DVector3& pos, short* pAngle, sectortype** cur
 		pSector->setzfrommap(LittleLong(load.ceilingz), LittleLong(load.floorz));
 		pSector->ceilingstat = ESectorFlags::FromInt(LittleShort(load.ceilingstat));
 		pSector->floorstat = ESectorFlags::FromInt(LittleShort(load.floorstat));
-		pSector->ceilingpicnum = LittleShort(load.ceilingpicnum);
+		pSector->ceilingpicnum = LittleShort(load.ceilingpic);
 		pSector->ceilingheinum = LittleShort(load.ceilingheinum);
-		pSector->floorpicnum = LittleShort(load.floorpicnum);
+		pSector->floorpicnum = LittleShort(load.floorpic);
 		pSector->floorheinum = LittleShort(load.floorheinum);
 		pSector->type = LittleShort(load.type);
 		pSector->hitag = LittleShort(load.hitag);
diff --git a/source/games/blood/src/fire.cpp b/source/games/blood/src/fire.cpp
index 96dfb7a7f..4183e095b 100644
--- a/source/games/blood/src/fire.cpp
+++ b/source/games/blood/src/fire.cpp
@@ -75,7 +75,7 @@ void DoFireFrame(void)
 		memcpy(FrameBuffer + 16896 + i * 128, SeedBuffer[nRand], 128);
 	}
 	CellularFrame(FrameBuffer, 128, 132);
-	auto pData = TileFiles.tileMakeWritable(2342);
+	auto pData = TileFiles.tileGet(2342);
 	uint8_t* pSource = FrameBuffer;
 	int x = fireSize;
 	do
diff --git a/source/games/blood/src/mapstructs.h b/source/games/blood/src/mapstructs.h
index 6adaeebe3..d0b8bcdea 100644
--- a/source/games/blood/src/mapstructs.h
+++ b/source/games/blood/src/mapstructs.h
@@ -27,10 +27,10 @@ struct sectortypedisk
 	int16_t wallptr, wallnum;
 	int32_t ceilingz, floorz;
 	uint16_t ceilingstat, floorstat;
-	int16_t ceilingpicnum, ceilingheinum;
+	int16_t ceilingpic, ceilingheinum;
 	int8_t ceilingshade;
 	uint8_t ceilingpal, ceilingxpanning, ceilingypanning;
-	int16_t floorpicnum, floorheinum;
+	int16_t floorpic, floorheinum;
 	int8_t floorshade;
 	uint8_t floorpal, floorxpanning, floorypanning;
 	uint8_t visibility, fogpal;
diff --git a/source/games/blood/src/mirrors.cpp b/source/games/blood/src/mirrors.cpp
index 83733955d..be9ecea73 100644
--- a/source/games/blood/src/mirrors.cpp
+++ b/source/games/blood/src/mirrors.cpp
@@ -47,10 +47,6 @@ void InitMirrors(void)
 	tileDelete(504);
 	portalClear();
 
-	for (int i = 0; i < 16; i++)
-	{
-		tileDelete(4080 + i);
-	}
 	for (int i = (int)wall.Size() - 1; i >= 0; i--)
 	{
 		auto pWalli = &wall[i];
@@ -131,7 +127,6 @@ void InitMirrors(void)
 			mirror[mirrorcnt].diff = link2->spr.pos - link->spr.pos;
 			mirror[mirrorcnt].mynum = i;
 			mirror[mirrorcnt].link = j;
-			secti->floorpicnum = 4080 + mirrorcnt;
 			secti->portalflags = PORTAL_SECTOR_FLOOR;
 			secti->portalnum = portalAdd(PORTAL_SECTOR_FLOOR, j, mirror[mirrorcnt].diff);
 			mirrorcnt++;
@@ -139,7 +134,6 @@ void InitMirrors(void)
 			mirror[mirrorcnt].diff = link->spr.pos - link2->spr.pos;
 			mirror[mirrorcnt].mynum = j;
 			mirror[mirrorcnt].link = i;
-			sectj->ceilingpicnum = 4080 + mirrorcnt;
 			sectj->portalflags = PORTAL_SECTOR_CEILING;
 			sectj->portalnum = portalAdd(PORTAL_SECTOR_CEILING, i, mirror[mirrorcnt].diff);
 			mirrorcnt++;
diff --git a/source/games/blood/src/tile.cpp b/source/games/blood/src/tile.cpp
index b1043727e..a98fd9382 100644
--- a/source/games/blood/src/tile.cpp
+++ b/source/games/blood/src/tile.cpp
@@ -34,14 +34,19 @@ BEGIN_BLD_NS
 
 int nTileFiles = 0;
 
-int tileStart[256];
-int tileEnd[256];
-int hTileFile[256];
-
 uint8_t surfType[kMaxTiles];
 int8_t tileShade[kMaxTiles];
 short voxelIndex[kMaxTiles];
 
+struct TextureProps
+{
+    uint8_t surfType;
+    int8_t tileShade;
+    int16_t voxelIndex;
+};
+
+TArray<TextureProps> tprops;
+
 #define x(a, b) registerName(#a, b);
 static void SetTileNames()
 {
@@ -92,6 +97,16 @@ void GameInterface::LoadGameTextures()
     SetTileNames();
 }
 
+void GameInterface::SetupSpecialTextures()
+{
+    // set up all special tiles here, before we fully hook up with the texture manager.
+    tileDelete(504);
+    TileFiles.tileCreate(4077, kLensSize, kLensSize);
+    TileFiles.tileCreate(4079, 128, 128);
+    TileFiles.tileMakeWritable(2342);
+    TileFiles.lock();   // from this point on the tile<->texture associations may not change anymore.
+}
+
 //---------------------------------------------------------------------------
 //
 // 
diff --git a/source/games/blood/src/view.cpp b/source/games/blood/src/view.cpp
index 3fb5958c4..58c91c5ba 100644
--- a/source/games/blood/src/view.cpp
+++ b/source/games/blood/src/view.cpp
@@ -155,7 +155,7 @@ void viewInit(void)
 		lensTable[i] = LittleLong(lensTable[i]);
 	}
 #endif
-	uint8_t* data = TileFiles.tileCreate(4077, kLensSize, kLensSize);
+	uint8_t* data = TileFiles.tileGet(4077);
 	memset(data, TRANSPARENT_INDEX, kLensSize * kLensSize);
 
 	for (int i = 0; i < 16; i++)
@@ -544,10 +544,6 @@ void renderCrystalBall()
 	}
 	PLAYER* pOther = &gPlayer[i];
 	//othercameraclock = PlayClock + MulScale(4, (int)gInterpolate, 16);;
-	if (!tileData(4079))
-	{
-		TileFiles.tileCreate(4079, 128, 128);
-	}
 	//renderSetTarget(4079, 128, 128);
 	renderSetAspect(65536, 78643);
 	int vd8 = pOther->actor->spr.x;
diff --git a/source/games/duke/src/premap.cpp b/source/games/duke/src/premap.cpp
index 31e6f71d9..0edffbf80 100644
--- a/source/games/duke/src/premap.cpp
+++ b/source/games/duke/src/premap.cpp
@@ -1203,8 +1203,6 @@ void exitlevel(MapRecord* nextlevel)
 		// MP scoreboard
 		ShowScoreboard(playerswhenstarted, [=](bool)
 			{
-			// Clear potentially loaded per-map ART only after the bonus screens.
-			artClearMapArt();
 			gameaction = ga_level;
 			ud.eog = false;
 			if (endofgame)
@@ -1227,8 +1225,6 @@ void exitlevel(MapRecord* nextlevel)
 		// SP cutscene + summary
 		ShowIntermission(currentLevel, nextlevel, &info, [=](bool)
 		{
-			// Clear potentially loaded per-map ART only after the bonus screens.
-			artClearMapArt();
 			ud.eog = false;
 			gameaction = endofgame? ga_startup : ga_nextlevel;
 		});