diff --git a/code/_helpers/icon_smoothing.dm b/code/_helpers/icon_smoothing.dm
index 41c0af5881b..de17f6c276e 100644
--- a/code/_helpers/icon_smoothing.dm
+++ b/code/_helpers/icon_smoothing.dm
@@ -69,60 +69,62 @@
 /turf/unsimulated/wall
 	smooth_underlays = TRUE
 
-/proc/calculate_adjacencies(atom/A)
-	if(!A.loc)
+/atom/proc/calculate_adjacencies()
+	if (!loc)
 		return 0
 
 	var/adjacencies = 0
 
 	var/atom/movable/AM
-	if(istype(A, /atom/movable))
-		AM = A
-		if(AM.can_be_unanchored && !AM.anchored)
-			return 0
 
 	for(var/direction in cardinal)
-		AM = find_type_in_direction(A, direction)
+		AM = find_type_in_direction(src, direction)
 		if(AM == NULLTURF_BORDER)
-			if((A.smooth & SMOOTH_BORDER))
+			if((smooth & SMOOTH_BORDER))
 				adjacencies |= 1 << direction
 		else if( (AM && !istype(AM)) || (istype(AM) && AM.anchored) )
 			adjacencies |= 1 << direction
 
 	if(adjacencies & N_NORTH)
 		if(adjacencies & N_WEST)
-			AM = find_type_in_direction(A, NORTHWEST)
+			AM = find_type_in_direction(src, NORTHWEST)
 			if(AM == NULLTURF_BORDER)
-				if((A.smooth & SMOOTH_BORDER))
+				if((smooth & SMOOTH_BORDER))
 					adjacencies |= N_NORTHWEST
 			else if( (AM && !istype(AM)) || (istype(AM) && AM.anchored) )
 				adjacencies |= N_NORTHWEST
 		if(adjacencies & N_EAST)
-			AM = find_type_in_direction(A, NORTHEAST)
+			AM = find_type_in_direction(src, NORTHEAST)
 			if(AM == NULLTURF_BORDER)
-				if((A.smooth & SMOOTH_BORDER))
+				if((smooth & SMOOTH_BORDER))
 					adjacencies |= N_NORTHEAST
 			else if( (AM && !istype(AM)) || (istype(AM) && AM.anchored) )
 				adjacencies |= N_NORTHEAST
 
 	if(adjacencies & N_SOUTH)
 		if(adjacencies & N_WEST)
-			AM = find_type_in_direction(A, SOUTHWEST)
+			AM = find_type_in_direction(src, SOUTHWEST)
 			if(AM == NULLTURF_BORDER)
-				if((A.smooth & SMOOTH_BORDER))
+				if((smooth & SMOOTH_BORDER))
 					adjacencies |= N_SOUTHWEST
 			else if( (AM && !istype(AM)) || (istype(AM) && AM.anchored) )
 				adjacencies |= N_SOUTHWEST
 		if(adjacencies & N_EAST)
-			AM = find_type_in_direction(A, SOUTHEAST)
+			AM = find_type_in_direction(src, SOUTHEAST)
 			if(AM == NULLTURF_BORDER)
-				if((A.smooth & SMOOTH_BORDER))
+				if((smooth & SMOOTH_BORDER))
 					adjacencies |= N_SOUTHEAST
 			else if( (AM && !istype(AM)) || (istype(AM) && AM.anchored) )
 				adjacencies |= N_SOUTHEAST
 
 	return adjacencies
 
+/atom/movable/calculate_adjacencies()
+	if (can_be_unanchored && !anchored)
+		return 0
+
+	return ..()
+
 //do not use, use queue_smooth(atom)
 /proc/smooth_icon(atom/A)
 	if(!A || !A.smooth)
@@ -133,7 +135,7 @@
 	if(QDELETED(A))
 		return
 	if((A.smooth & SMOOTH_TRUE) || (A.smooth & SMOOTH_MORE))
-		var/adjacencies = calculate_adjacencies(A)
+		var/adjacencies = A.calculate_adjacencies()
 
 		if(A.smooth & SMOOTH_DIAGONAL)
 			A.diagonal_smooth(adjacencies)
@@ -172,7 +174,7 @@
 	if (smooth_underlays && adjacencies)
 		// This should be a mutable_appearance, but we're still on 510.
 		// Alas.
-		var/image/underlay_appearance = image(layer = TURF_LAYER)
+		var/mutable_appearance/underlay_appearance = new(layer = TURF_LAYER)
 		var/list/U = list(underlay_appearance)
 		if(fixed_underlay)
 			if(fixed_underlay["space"])
@@ -257,33 +259,103 @@
 			se = "4-e"
 
 	var/list/New
+	var/list/Old
 
 	if(A.top_left_corner != nw)
-		A.cut_overlay(A.top_left_corner)
+		if (A.top_left_corner)
+			LAZYADD(Old, A.top_left_corner)
 		A.top_left_corner = nw
 		LAZYADD(New, nw)
 
 	if(A.top_right_corner != ne)
-		A.cut_overlay(A.top_right_corner)
+		if (A.top_right_corner)
+			LAZYADD(Old, A.top_right_corner)
 		A.top_right_corner = ne
 		LAZYADD(New, ne)
 
 	if(A.bottom_right_corner != sw)
-		A.cut_overlay(A.bottom_right_corner)
+		if (A.bottom_right_corner)
+			LAZYADD(Old, A.bottom_right_corner)
 		A.bottom_right_corner = sw
 		LAZYADD(New, sw)
 
 	if(A.bottom_left_corner != se)
-		A.cut_overlay(A.bottom_left_corner)
+		if (A.bottom_left_corner)
+			LAZYADD(Old, A.bottom_left_corner)
 		A.bottom_left_corner = se
 		LAZYADD(New, se)
 
+	if(Old)
+		A.cut_overlay(Old)
+
 	if(New)
 		A.add_overlay(New)
 
 	if (A.icon_state && !(A.smooth & SMOOTH_NO_CLEAR_ICON))
 		A.icon_state = null
 
+// A more stripped down version of the above, meant for using images to apply multiple smooth overlays
+//    at once.
+/proc/cardinal_smooth_fromicon(icon/I, adjacencies)
+	//NW CORNER
+	var/nw = "1-i"
+	if((adjacencies & N_NORTH) && (adjacencies & N_WEST))
+		if(adjacencies & N_NORTHWEST)
+			nw = "1-f"
+		else
+			nw = "1-nw"
+	else
+		if(adjacencies & N_NORTH)
+			nw = "1-n"
+		else if(adjacencies & N_WEST)
+			nw = "1-w"
+
+	//NE CORNER
+	var/ne = "2-i"
+	if((adjacencies & N_NORTH) && (adjacencies & N_EAST))
+		if(adjacencies & N_NORTHEAST)
+			ne = "2-f"
+		else
+			ne = "2-ne"
+	else
+		if(adjacencies & N_NORTH)
+			ne = "2-n"
+		else if(adjacencies & N_EAST)
+			ne = "2-e"
+
+	//SW CORNER
+	var/sw = "3-i"
+	if((adjacencies & N_SOUTH) && (adjacencies & N_WEST))
+		if(adjacencies & N_SOUTHWEST)
+			sw = "3-f"
+		else
+			sw = "3-sw"
+	else
+		if(adjacencies & N_SOUTH)
+			sw = "3-s"
+		else if(adjacencies & N_WEST)
+			sw = "3-w"
+
+	//SE CORNER
+	var/se = "4-i"
+	if((adjacencies & N_SOUTH) && (adjacencies & N_EAST))
+		if(adjacencies & N_SOUTHEAST)
+			se = "4-f"
+		else
+			se = "4-se"
+	else
+		if(adjacencies & N_SOUTH)
+			se = "4-s"
+		else if(adjacencies & N_EAST)
+			se = "4-e"
+
+	var/image/nw_i = image(I, nw)
+	var/image/ne_i = image(I, ne)
+	var/image/sw_i = image(I, sw)
+	var/image/se_i = image(I, se)
+
+	return list(nw_i, ne_i, sw_i, se_i)
+
 /proc/find_type_in_direction(atom/source, direction)
 	var/turf/target_turf = get_step(source, direction)
 	if(!target_turf)
@@ -332,13 +404,10 @@
 					queue_smooth(A)
 
 /atom/proc/clear_smooth_overlays()
-	cut_overlay(top_left_corner)
+	cut_overlay(list(top_left_corner, top_right_corner, bottom_left_corner, bottom_right_corner))
 	top_left_corner = null
-	cut_overlay(top_right_corner)
 	top_right_corner = null
-	cut_overlay(bottom_right_corner)
 	bottom_right_corner = null
-	cut_overlay(bottom_left_corner)
 	bottom_left_corner = null
 
 /atom/proc/replace_smooth_overlays(nw, ne, sw, se)
diff --git a/code/game/turfs/simulated/wall_icon.dm b/code/game/turfs/simulated/wall_icon.dm
index 7852ebef3e3..9b5ece8e412 100644
--- a/code/game/turfs/simulated/wall_icon.dm
+++ b/code/game/turfs/simulated/wall_icon.dm
@@ -11,6 +11,9 @@
 		material = get_material_by_name(DEFAULT_WALL_MATERIAL)
 	if(material)
 		explosion_resistance = material.explosion_resistance
+		if (material.wall_icon)
+			icon = material.wall_icon
+
 	if(reinf_material && reinf_material.explosion_resistance > explosion_resistance)
 		explosion_resistance = reinf_material.explosion_resistance
 
@@ -26,10 +29,8 @@
 	else if(material.opacity < 0.5 && opacity)
 		set_light(0)
 
-	update_connections(1)
 	update_icon()
 
-
 /turf/simulated/wall/proc/set_material(var/material/newmaterial, var/material/newrmaterial)
 	material = newmaterial
 	reinf_material = newrmaterial
@@ -42,37 +43,43 @@
 	if(!damage_overlays[1]) //list hasn't been populated
 		generate_overlays()
 
-	cut_overlays()
+	var/list/cutlist = (reinforcement_images||list()) + damage_image
+	cut_overlay(cutlist, TRUE)
+	LAZYCLEARLIST(reinforcement_images)
+	damage_image = null
+
 	var/list/overlays_to_add = list()
-	var/image/I
 
-	if(!density)
-		I = image('icons/turf/wall_masks.dmi', "[material.icon_base]fwall_open")
-		I.color = material.icon_colour
-		add_overlay(I)
+	if (!density)	// We're a fake and we're open.
+		clear_smooth_overlays()
+		fake_wall_image = image('icons/turf/wall_masks.dmi', "[material.icon_base]fwall_open")
+		fake_wall_image.color = material.icon_colour
+		add_overlay(fake_wall_image)
+		smooth = SMOOTH_FALSE
 		return
+	else if (fake_wall_image)
+		cut_overlay(fake_wall_image)
+		fake_wall_image = null
+		smooth = initial(smooth)
 
-	for(var/i = 1 to 4)
-		I = image('icons/turf/wall_masks.dmi', "[material.icon_base][wall_connections[i]]", dir = 1<<(i-1))
-		I.color = material.icon_colour
-		overlays_to_add += I
+	calculate_adjacencies()	// Update cached_adjacency
 
 	if(reinf_material)
+		var/image/I
 		if(construction_stage != null && construction_stage < 6)
 			I = image('icons/turf/wall_masks.dmi', "reinf_construct-[construction_stage]")
 			I.color = reinf_material.icon_colour
-			overlays_to_add += I
+			LAZYADD(reinforcement_images, I)
 		else
-			if("[reinf_material.icon_reinf]0" in icon_states('icons/turf/wall_masks.dmi'))
-				// Directional icon
-				for(var/i = 1 to 4)
-					I = image('icons/turf/wall_masks.dmi', "[reinf_material.icon_reinf][wall_connections[i]]", dir = 1<<(i-1))
-					I.color = reinf_material.icon_colour
-					overlays_to_add += I
+			if (reinf_material.multipart_reinf_icon)
+				LAZYADD(reinforcement_images, cardinal_smooth_fromicon(reinf_material.multipart_reinf_icon, cached_adjacency))
 			else
 				I = image('icons/turf/wall_masks.dmi', reinf_material.icon_reinf)
 				I.color = reinf_material.icon_colour
-				overlays_to_add += I
+				LAZYADD(reinforcement_images, I)
+
+		if (reinforcement_images)
+			overlays_to_add += reinforcement_images
 
 	if(damage != 0)
 		var/integrity = material.integrity
@@ -83,9 +90,12 @@
 		if(overlay > damage_overlays.len)
 			overlay = damage_overlays.len
 
-		overlays_to_add += damage_overlays[overlay]
+		damage_image = damage_overlays[overlay]
+		overlays_to_add += damage_image
 
-	add_overlay(overlays_to_add)
+	add_overlay(overlays_to_add, TRUE)
+	UNSETEMPTY(reinforcement_images)
+	queue_smooth(src)
 
 /turf/simulated/wall/proc/generate_overlays()
 	var/alpha_inc = 256 / damage_overlays.len
@@ -96,23 +106,50 @@
 		img.alpha = (i * alpha_inc) - 1
 		damage_overlays[i] = img
 
-
-/turf/simulated/wall/proc/update_connections(propagate = 0)
-	if(!material)
+/turf/simulated/wall/calculate_adjacencies()
+	. = 0
+	if (!loc || !material)
 		return
-	var/list/dirs = list()
-	for(var/turf/simulated/wall/W in orange(src, 1))
-		if(!W.material)
-			continue
-		if(propagate)
-			W.update_connections()
-			W.update_icon()
-		if(can_join_with(W))
-			dirs += get_dir(src, W)
 
-	wall_connections = dirs_to_corner_states(dirs)
+	var/turf/simulated/wall/W
+	var/material/M
+	var/our_icon_base = material.icon_base
 
-/turf/simulated/wall/proc/can_join_with(var/turf/simulated/wall/W)
-	if(material && W.material && material.icon_base == W.material.icon_base)
-		return 1
-	return 0
+	for (var/dir in cardinal)
+		W = get_step(src, dir)
+		if (istype(W) && (W.smooth || !W.density))
+			M = W.material
+			if (M && M.icon_base == our_icon_base)
+				. |= 1 << dir
+
+	if (. & N_NORTH)
+		if (. & N_WEST)
+			W = get_step(src, NORTHWEST)
+			if (istype(W) && (W.smooth || !W.density))
+				M = W.material
+				if (M && M.icon_base == our_icon_base)
+					. |= N_NORTHWEST
+
+		if (. & N_EAST)
+			W = get_step(src, NORTHEAST)
+			if (istype(W) && (W.smooth || !W.density))
+				M = W.material
+				if (M && M.icon_base == our_icon_base)
+					. |= N_NORTHEAST
+
+	if (. & N_SOUTH)
+		if (. & N_WEST)
+			W = get_step(src, SOUTHWEST)
+			if (istype(W) && (W.smooth || !W.density))
+				M = W.material
+				if (M && M.icon_base == our_icon_base)
+					. |= N_SOUTHWEST
+
+		if (. & N_EAST)
+			W = get_step(src, SOUTHEAST)
+			if (istype(W) && (W.smooth || !W.density))
+				M = W.material
+				if (M && M.icon_base == our_icon_base)
+					. |= N_SOUTHEAST
+
+	cached_adjacency = .
diff --git a/code/game/turfs/simulated/walls.dm b/code/game/turfs/simulated/walls.dm
index e8b3fb10e34..33754cc3909 100644
--- a/code/game/turfs/simulated/walls.dm
+++ b/code/game/turfs/simulated/walls.dm
@@ -19,7 +19,12 @@
 	var/last_state
 	var/construction_stage
 
-	var/list/wall_connections = list("0", "0", "0", "0")
+	var/tmp/list/image/reinforcement_images
+	var/tmp/image/damage_image
+	var/tmp/image/fake_wall_image
+	var/tmp/cached_adjacency
+
+	smooth = SMOOTH_TRUE | SMOOTH_NO_CLEAR_ICON
 
 // Walls always hide the stuff below them.
 /turf/simulated/wall/levelupdate(mapload)
@@ -178,7 +183,6 @@
 	clear_plants()
 	material = get_material_by_name("placeholder")
 	reinf_material = null
-	update_connections(1)
 
 	if (!no_change)
 		ChangeTurf(/turf/simulated/floor/plating)
diff --git a/code/game/turfs/turf.dm b/code/game/turfs/turf.dm
index 95af62a6f50..e8254f76df2 100644
--- a/code/game/turfs/turf.dm
+++ b/code/game/turfs/turf.dm
@@ -81,9 +81,7 @@
 	..()
 	return QDEL_HINT_IWILLGC
 
-// This should be using mutable_appearance, but 510. Woe.
-// Update this & all overrides if/when we move to 511.
-/turf/proc/get_smooth_underlay_icon(image/underlay_appearance, turf/asking_turf, adjacency_dir)
+/turf/proc/get_smooth_underlay_icon(mutable_appearance/underlay_appearance, turf/asking_turf, adjacency_dir)
 	underlay_appearance.icon = icon
 	underlay_appearance.icon_state = icon_state
 	underlay_appearance.dir = adjacency_dir
diff --git a/code/modules/materials/materials.dm b/code/modules/materials/materials.dm
index 5c478e799ea..6b241044ae9 100644
--- a/code/modules/materials/materials.dm
+++ b/code/modules/materials/materials.dm
@@ -83,6 +83,8 @@ var/list/name_to_material
 	var/door_icon_base = "metal"                         // Door base icon tag. See header.
 	var/icon_reinf = "reinf_metal"                       // Overlay used
 	var/list/stack_origin_tech = list(TECH_MATERIAL = 1) // Research level for stacks.
+	var/icon/wall_icon
+	var/icon/multipart_reinf_icon
 
 	// Attributes
 	var/cut_delay = 0            // Delay in ticks when cutting through this wall.
@@ -153,6 +155,31 @@ var/list/name_to_material
 	if(!shard_icon)
 		shard_icon = shard_type
 
+	var/skip_blend = FALSE
+	switch (icon_base)
+		if ("solid")
+			wall_icon = 'icons/turf/smooth/composite_solid.dmi'
+		if ("stone")
+			wall_icon = 'icons/turf/smooth/composite_stone.dmi'
+			multipart_reinf_icon = 'icons/turf/smooth/composite_stone_reinf.dmi'
+		if ("metal")
+			wall_icon = 'icons/turf/smooth/composite_metal.dmi'
+		if ("cult")
+			wall_icon = 'icons/turf/smooth/cult_wall.dmi'
+			skip_blend = TRUE
+		if ("arust")
+			wall_icon = 'icons/turf/smooth/rusty_wall.dmi'
+			skip_blend = TRUE
+		else
+			world.log << "materials: [src] has unknown icon_base [icon_base]."
+
+	if (wall_icon && icon_colour && !skip_blend)
+		wall_icon = new(wall_icon)
+		wall_icon.Blend(icon_colour, ICON_MULTIPLY)
+		if (multipart_reinf_icon)
+			multipart_reinf_icon = new(multipart_reinf_icon)
+			multipart_reinf_icon.Blend(icon_colour, ICON_MULTIPLY)
+
 // This is a placeholder for proper integration of windows/windoors into the system.
 /material/proc/build_windows(var/mob/living/user, var/obj/item/stack/used_stack)
 	return 0
@@ -599,6 +626,7 @@ var/list/name_to_material
 	stack_type = null
 	icon_colour = "#B7410E"
 	icon_base = "arust"
+	icon_reinf = "reinf_over"
 	integrity = 250
 	explosion_resistance = 8
 	hardness = 15
diff --git a/code/modules/mining/mine_turfs.dm b/code/modules/mining/mine_turfs.dm
index 2a870820cf9..20732bb630c 100644
--- a/code/modules/mining/mine_turfs.dm
+++ b/code/modules/mining/mine_turfs.dm
@@ -541,7 +541,7 @@
 
 	return INITIALIZE_HINT_NORMAL
 
-/turf/simulated/floor/asteroid/get_smooth_underlay_icon(image/underlay_appearance, turf/asking_turf, adjacency_dir)
+/turf/simulated/floor/asteroid/get_smooth_underlay_icon(mutable_appearance/underlay_appearance, turf/asking_turf, adjacency_dir)
 	. = ..()
 	underlay_appearance.pixel_x = pixel_x
 	underlay_appearance.pixel_y = pixel_y
diff --git a/code/modules/multiz/turf.dm b/code/modules/multiz/turf.dm
index 14c376e8969..1dcec55faca 100644
--- a/code/modules/multiz/turf.dm
+++ b/code/modules/multiz/turf.dm
@@ -102,7 +102,7 @@
 
 	return ..()
 
-/turf/simulated/open/get_smooth_underlay_icon(image/underlay_appearance, turf/asking_turf, adjacency_dir)
+/turf/simulated/open/get_smooth_underlay_icon(mutable_appearance/underlay_appearance, turf/asking_turf, adjacency_dir)
 	underlay_appearance.appearance = src
 	return TRUE
 
diff --git a/icons/turf/smooth/composite_metal.dmi b/icons/turf/smooth/composite_metal.dmi
new file mode 100644
index 00000000000..790dc927ea1
Binary files /dev/null and b/icons/turf/smooth/composite_metal.dmi differ
diff --git a/icons/turf/smooth/composite_solid.dmi b/icons/turf/smooth/composite_solid.dmi
new file mode 100644
index 00000000000..1b6543b0a0d
Binary files /dev/null and b/icons/turf/smooth/composite_solid.dmi differ
diff --git a/icons/turf/smooth/composite_stone.dmi b/icons/turf/smooth/composite_stone.dmi
new file mode 100644
index 00000000000..f28713ddf6b
Binary files /dev/null and b/icons/turf/smooth/composite_stone.dmi differ
diff --git a/icons/turf/smooth/composite_stone_reinf.dmi b/icons/turf/smooth/composite_stone_reinf.dmi
new file mode 100644
index 00000000000..3130586fae7
Binary files /dev/null and b/icons/turf/smooth/composite_stone_reinf.dmi differ
diff --git a/icons/turf/smooth/rusty_wall.dmi b/icons/turf/smooth/rusty_wall.dmi
new file mode 100644
index 00000000000..5db142a83b9
Binary files /dev/null and b/icons/turf/smooth/rusty_wall.dmi differ