diff --git a/src/p_saveg.c b/src/p_saveg.c
index c876713e4..5af72cd46 100644
--- a/src/p_saveg.c
+++ b/src/p_saveg.c
@@ -777,15 +777,13 @@ static void P_NetArchiveWorld(void)
 	size_t i;
 	INT32 statsec = 0, statline = 0;
 	const line_t *li = lines;
+	const line_t *spawnli = spawnlines;
 	const side_t *si;
+	const side_t *spawnsi;
 	UINT8 *put;
 
-	// reload the map just to see difference
-	virtres_t* virt = vres_GetMap(lastloadedmaplumpnum);
-	mapsector_t  *ms  = (mapsector_t*) vres_Find(virt, "SECTORS")->data;
-	mapsidedef_t *msd = (mapsidedef_t*) vres_Find(virt, "SIDEDEFS")->data;
-	maplinedef_t *mld = (maplinedef_t*) vres_Find(virt, "LINEDEFS")->data;
 	const sector_t *ss = sectors;
+	const sector_t *spawnss = spawnsectors;
 	UINT8 diff, diff2, diff3;
 
 	// initialize colormap vars because paranoia
@@ -794,45 +792,45 @@ static void P_NetArchiveWorld(void)
 	WRITEUINT32(save_p, ARCHIVEBLOCK_WORLD);
 	put = save_p;
 
-	for (i = 0; i < numsectors; i++, ss++, ms++)
+	for (i = 0; i < numsectors; i++, ss++, spawnss++)
 	{
 		diff = diff2 = diff3 = 0;
-		if (ss->floorheight != SHORT(ms->floorheight)<<FRACBITS)
+		if (ss->floorheight != spawnss->floorheight)
 			diff |= SD_FLOORHT;
-		if (ss->ceilingheight != SHORT(ms->ceilingheight)<<FRACBITS)
+		if (ss->ceilingheight != spawnss->ceilingheight)
 			diff |= SD_CEILHT;
 		//
 		// flats
 		//
-		if (ss->floorpic != P_CheckLevelFlat(ms->floorpic))
+		if (ss->floorpic != spawnss->floorpic)
 			diff |= SD_FLOORPIC;
-		if (ss->ceilingpic != P_CheckLevelFlat(ms->ceilingpic))
+		if (ss->ceilingpic != spawnss->ceilingpic)
 			diff |= SD_CEILPIC;
 
-		if (ss->lightlevel != SHORT(ms->lightlevel))
+		if (ss->lightlevel != spawnss->lightlevel)
 			diff |= SD_LIGHT;
-		if (ss->special != SHORT(ms->special))
+		if (ss->special != spawnss->special)
 			diff |= SD_SPECIAL;
 
-		if (ss->floor_xoffs != ss->spawn_flr_xoffs)
+		if (ss->floor_xoffs != spawnss->floor_xoffs)
 			diff2 |= SD_FXOFFS;
-		if (ss->floor_yoffs != ss->spawn_flr_yoffs)
+		if (ss->floor_yoffs != spawnss->floor_yoffs)
 			diff2 |= SD_FYOFFS;
-		if (ss->ceiling_xoffs != ss->spawn_ceil_xoffs)
+		if (ss->ceiling_xoffs != spawnss->ceiling_xoffs)
 			diff2 |= SD_CXOFFS;
-		if (ss->ceiling_yoffs != ss->spawn_ceil_yoffs)
+		if (ss->ceiling_yoffs != spawnss->ceiling_yoffs)
 			diff2 |= SD_CYOFFS;
-		if (ss->floorpic_angle != ss->spawn_flrpic_angle)
+		if (ss->floorpic_angle != spawnss->floorpic_angle)
 			diff2 |= SD_FLOORANG;
-		if (ss->ceilingpic_angle != ss->spawn_flrpic_angle)
+		if (ss->ceilingpic_angle != spawnss->ceilingpic_angle)
 			diff2 |= SD_CEILANG;
 
-		if (ss->tag != SHORT(ms->tag))
+		if (ss->tag != spawnss->tag)
 			diff2 |= SD_TAG;
-		if (ss->nexttag != ss->spawn_nexttag || ss->firsttag != ss->spawn_firsttag)
+		if (ss->nexttag != spawnss->nexttag || ss->firsttag != spawnss->firsttag)
 			diff3 |= SD_TAGLIST;
 
-		if (ss->extra_colormap != ss->spawn_extra_colormap)
+		if (ss->extra_colormap != spawnss->extra_colormap)
 			diff3 |= SD_COLORMAP;
 
 		// Check if any of the sector's FOFs differ from how they spawned
@@ -936,45 +934,41 @@ static void P_NetArchiveWorld(void)
 	WRITEUINT16(put, 0xffff);
 
 	// do lines
-	for (i = 0; i < numlines; i++, mld++, li++)
+	for (i = 0; i < numlines; i++, spawnli++, li++)
 	{
 		diff = diff2 = diff3 = 0;
 
-		if (li->special != SHORT(mld->special))
+		if (li->special != spawnli->special)
 			diff |= LD_SPECIAL;
 
-		if (SHORT(mld->special) == 321 || SHORT(mld->special) == 322) // only reason li->callcount would be non-zero is if either of these are involved
+		if (spawnli->special == 321 || spawnli->special == 322) // only reason li->callcount would be non-zero is if either of these are involved
 			diff |= LD_CLLCOUNT;
 
 		if (li->sidenum[0] != 0xffff)
 		{
 			si = &sides[li->sidenum[0]];
-			if (si->textureoffset != SHORT(msd[li->sidenum[0]].textureoffset)<<FRACBITS)
+			spawnsi = &spawnsides[li->sidenum[0]];
+			if (si->textureoffset != spawnsi->textureoffset)
 				diff |= LD_S1TEXOFF;
 			//SoM: 4/1/2000: Some textures are colormaps. Don't worry about invalid textures.
-			if (R_CheckTextureNumForName(msd[li->sidenum[0]].toptexture) != -1
-				&& si->toptexture != R_TextureNumForName(msd[li->sidenum[0]].toptexture))
+			if (si->toptexture != spawnsi->toptexture)
 				diff |= LD_S1TOPTEX;
-			if (R_CheckTextureNumForName(msd[li->sidenum[0]].bottomtexture) != -1
-				&& si->bottomtexture != R_TextureNumForName(msd[li->sidenum[0]].bottomtexture))
+			if (si->bottomtexture != spawnsi->bottomtexture)
 				diff |= LD_S1BOTTEX;
-			if (R_CheckTextureNumForName(msd[li->sidenum[0]].midtexture) != -1
-				&& si->midtexture != R_TextureNumForName(msd[li->sidenum[0]].midtexture))
+			if (si->midtexture != spawnsi->midtexture)
 				diff |= LD_S1MIDTEX;
 		}
 		if (li->sidenum[1] != 0xffff)
 		{
 			si = &sides[li->sidenum[1]];
-			if (si->textureoffset != SHORT(msd[li->sidenum[1]].textureoffset)<<FRACBITS)
+			spawnsi = &spawnsides[li->sidenum[1]];
+			if (si->textureoffset != spawnsi->textureoffset)
 				diff2 |= LD_S2TEXOFF;
-			if (R_CheckTextureNumForName(msd[li->sidenum[1]].toptexture) != -1
-				&& si->toptexture != R_TextureNumForName(msd[li->sidenum[1]].toptexture))
+			if (si->toptexture != spawnsi->toptexture)
 				diff2 |= LD_S2TOPTEX;
-			if (R_CheckTextureNumForName(msd[li->sidenum[1]].bottomtexture) != -1
-				&& si->bottomtexture != R_TextureNumForName(msd[li->sidenum[1]].bottomtexture))
+			if (si->bottomtexture != spawnsi->bottomtexture)
 				diff2 |= LD_S2BOTTEX;
-			if (R_CheckTextureNumForName(msd[li->sidenum[1]].midtexture) != -1
-				&& si->midtexture != R_TextureNumForName(msd[li->sidenum[1]].midtexture))
+			if (si->midtexture != spawnsi->midtexture)
 				diff2 |= LD_S2MIDTEX;
 			if (diff2)
 				diff |= LD_DIFF2;
@@ -1018,7 +1012,6 @@ static void P_NetArchiveWorld(void)
 	WRITEUINT16(put, 0xffff);
 	R_ClearTextureNumCache(false);
 
-	vres_Free(virt);
 	save_p = put;
 }
 
diff --git a/src/p_setup.c b/src/p_setup.c
index bc736588e..6e6c1a72b 100644
--- a/src/p_setup.c
+++ b/src/p_setup.c
@@ -103,6 +103,9 @@ node_t *nodes;
 line_t *lines;
 side_t *sides;
 mapthing_t *mapthings;
+sector_t *spawnsectors;
+line_t *spawnlines;
+side_t *spawnsides;
 INT32 numstarposts;
 UINT16 bossdisabled;
 boolean stoppedclock;
@@ -666,11 +669,9 @@ static void P_LoadRawSectors(UINT8 *data)
 		ss->ceilingpic = P_AddLevelFlat(ms->ceilingpic, foundflats);
 
 		ss->lightlevel = SHORT(ms->lightlevel);
-		ss->spawn_lightlevel = SHORT(ms->lightlevel);
 		ss->special = SHORT(ms->special);
 		ss->tag = SHORT(ms->tag);
 		ss->nexttag = ss->firsttag = -1;
-		ss->spawn_nexttag = ss->spawn_firsttag = -1;
 
 		memset(&ss->soundorg, 0, sizeof(ss->soundorg));
 		ss->validcount = 0;
@@ -705,9 +706,7 @@ static void P_LoadRawSectors(UINT8 *data)
 		ss->spawn_extra_colormap = NULL;
 
 		ss->floor_xoffs = ss->ceiling_xoffs = ss->floor_yoffs = ss->ceiling_yoffs = 0;
-		ss->spawn_flr_xoffs = ss->spawn_ceil_xoffs = ss->spawn_flr_yoffs = ss->spawn_ceil_yoffs = 0;
 		ss->floorpic_angle = ss->ceilingpic_angle = 0;
-		ss->spawn_flrpic_angle = ss->spawn_ceilpic_angle = 0;
 		ss->gravity = NULL;
 		ss->cullheight = NULL;
 		ss->verticalflip = false;
@@ -2775,6 +2774,15 @@ boolean P_SetupLevel(boolean skipprecip)
 		P_LoadLineDefs2();
 		P_GroupLines();
 
+		// Copy relevant map data for NetArchive purposes.
+		spawnsectors = Z_Calloc(numsectors * sizeof (*sectors), PU_LEVEL, NULL);
+		spawnlines = Z_Calloc(numlines * sizeof (*lines), PU_LEVEL, NULL);
+		spawnsides = Z_Calloc(numsides * sizeof (*sides), PU_LEVEL, NULL);
+
+		memcpy(spawnsectors, sectors, numsectors * sizeof (*sectors));
+		memcpy(spawnlines, lines, numlines * sizeof (*lines));
+		memcpy(spawnsides, sides, numsides * sizeof (*sides));
+
 		P_PrepareRawThings(vres_Find(virt, "THINGS")->data);
 
 		P_MakeMapMD5(virt, &mapmd5);
diff --git a/src/p_spec.c b/src/p_spec.c
index bf7f6210a..297c9a427 100644
--- a/src/p_spec.c
+++ b/src/p_spec.c
@@ -1603,8 +1603,6 @@ static inline void P_InitTagLists(void)
 		size_t j = (unsigned)sectors[i].tag % numsectors;
 		sectors[i].nexttag = sectors[j].firsttag;
 		sectors[j].firsttag = (INT32)i;
-		sectors[i].spawn_nexttag = sectors[i].nexttag;
-		sectors[j].spawn_firsttag = sectors[j].firsttag;
 	}
 
 	for (i = numlines - 1; i != (size_t)-1; i--)
@@ -6405,22 +6403,16 @@ static void P_ApplyFlatAlignment(line_t *master, sector_t *sector, angle_t flata
 {
 	if (!(master->flags & ML_NETONLY)) // Modify floor flat alignment unless ML_NETONLY flag is set
 	{
-		sector->spawn_flrpic_angle = sector->floorpic_angle = flatangle;
+		sector->floorpic_angle = flatangle;
 		sector->floor_xoffs += xoffs;
 		sector->floor_yoffs += yoffs;
-		// saved for netgames
-		sector->spawn_flr_xoffs = sector->floor_xoffs;
-		sector->spawn_flr_yoffs = sector->floor_yoffs;
 	}
 
 	if (!(master->flags & ML_NONET)) // Modify ceiling flat alignment unless ML_NONET flag is set
 	{
-		sector->spawn_ceilpic_angle = sector->ceilingpic_angle = flatangle;
+		sector->ceilingpic_angle = flatangle;
 		sector->ceiling_xoffs += xoffs;
 		sector->ceiling_yoffs += yoffs;
-		// saved for netgames
-		sector->spawn_ceil_xoffs = sector->ceiling_xoffs;
-		sector->spawn_ceil_yoffs = sector->ceiling_yoffs;
 	}
 
 }
diff --git a/src/r_defs.h b/src/r_defs.h
index 3cc780545..353dc572b 100644
--- a/src/r_defs.h
+++ b/src/r_defs.h
@@ -384,17 +384,6 @@ typedef struct sector_s
 	// for fade thinker
 	INT16 spawn_lightlevel;
 
-	// these are saved for netgames, so do not let Lua touch these!
-	INT32 spawn_nexttag, spawn_firsttag; // the actual nexttag/firsttag values may differ if the sector's tag was changed
-
-	// offsets sector spawned with (via linedef type 7)
-	fixed_t spawn_flr_xoffs, spawn_flr_yoffs;
-	fixed_t spawn_ceil_xoffs, spawn_ceil_yoffs;
-
-	// flag angles sector spawned with (via linedef type 7)
-	angle_t spawn_flrpic_angle;
-	angle_t spawn_ceilpic_angle;
-
 	// colormap structure
 	extracolormap_t *spawn_extra_colormap;
 } sector_t;
diff --git a/src/r_state.h b/src/r_state.h
index 75566923b..4e1eb388e 100644
--- a/src/r_state.h
+++ b/src/r_state.h
@@ -63,6 +63,7 @@ extern seg_t *segs;
 
 extern size_t numsectors;
 extern sector_t *sectors;
+extern sector_t *spawnsectors;
 
 extern size_t numsubsectors;
 extern subsector_t *subsectors;
@@ -72,9 +73,11 @@ extern node_t *nodes;
 
 extern size_t numlines;
 extern line_t *lines;
+extern line_t *spawnlines;
 
 extern size_t numsides;
 extern side_t *sides;
+extern side_t *spawnsides;
 
 //
 // POV data.