diff --git a/src/Sourcefile b/src/Sourcefile
index de90bb609..fb08c2171 100644
--- a/src/Sourcefile
+++ b/src/Sourcefile
@@ -64,6 +64,7 @@ r_skins.c
 r_sky.c
 r_splats.c
 r_things.c
+r_bbox.c
 r_textures.c
 r_patch.c
 r_patchrotation.c
diff --git a/src/d_netcmd.c b/src/d_netcmd.c
index 4e90db0dc..ceb94fb1f 100644
--- a/src/d_netcmd.c
+++ b/src/d_netcmd.c
@@ -868,6 +868,7 @@ void D_RegisterClientCommands(void)
 	// screen.c
 	CV_RegisterVar(&cv_fullscreen);
 	CV_RegisterVar(&cv_renderview);
+	CV_RegisterVar(&cv_renderhitbox);
 	CV_RegisterVar(&cv_renderer);
 	CV_RegisterVar(&cv_scr_depth);
 	CV_RegisterVar(&cv_scr_width);
diff --git a/src/p_mobj.h b/src/p_mobj.h
index 60601692c..a7e25f461 100644
--- a/src/p_mobj.h
+++ b/src/p_mobj.h
@@ -122,7 +122,7 @@ typedef enum
 	MF_AMBIENT          = 1<<10,
 	// Slide this object when it hits a wall.
 	MF_SLIDEME          = 1<<11,
-	// Player cheat.
+	// Don't collide with walls or solid objects. Two MF_NOCLIP objects can't touch each other at all!
 	MF_NOCLIP           = 1<<12,
 	// Allow moves to any height, no gravity. For active floaters.
 	MF_FLOAT            = 1<<13,
diff --git a/src/r_bbox.c b/src/r_bbox.c
new file mode 100644
index 000000000..e3b5216bf
--- /dev/null
+++ b/src/r_bbox.c
@@ -0,0 +1,290 @@
+// SONIC ROBO BLAST 2
+//-----------------------------------------------------------------------------
+// Copyright (C) 1993-1996 by id Software, Inc.
+// Copyright (C) 1998-2000 by DooM Legacy Team.
+// Copyright (C) 1999-2021 by Sonic Team Junior.
+// Copyright (C)      2022 by Kart Krew.
+//
+// This program is free software distributed under the
+// terms of the GNU General Public License, version 2.
+// See the 'LICENSE' file for more details.
+//-----------------------------------------------------------------------------
+/// \file  r_bbox.c
+/// \brief Boundary box (cube) renderer
+
+#include "doomdef.h"
+#include "command.h"
+#include "r_local.h"
+#include "screen.h" // cv_renderhitbox
+#include "v_video.h" // V_DrawFill
+
+enum {
+	RENDERHITBOX_OFF,
+	RENDERHITBOX_TANGIBLE,
+	RENDERHITBOX_ALL,
+	RENDERHITBOX_INTANGIBLE,
+	RENDERHITBOX_RINGS,
+};
+
+static CV_PossibleValue_t renderhitbox_cons_t[] = {
+	{RENDERHITBOX_OFF, "Off"},
+	{RENDERHITBOX_TANGIBLE, "Tangible"},
+	{RENDERHITBOX_ALL, "All"},
+	{RENDERHITBOX_INTANGIBLE, "Intangible"},
+	{RENDERHITBOX_RINGS, "Rings"},
+	{0}};
+
+consvar_t cv_renderhitbox = CVAR_INIT ("renderhitbox", "Off", 0, renderhitbox_cons_t, NULL);
+
+struct bbox_col {
+	INT32 x;
+	INT32 y;
+	INT32 h;
+};
+
+struct bbox_config {
+	fixed_t height;
+	fixed_t tz;
+	struct bbox_col col[4];
+	UINT8 color;
+};
+
+static inline void
+raster_bbox_seg
+(		INT32 x,
+		fixed_t y,
+		fixed_t h,
+		UINT8 pixel)
+{
+	y /= FRACUNIT;
+
+	if (y < 0)
+		y = 0;
+
+	h = y + (FixedCeil(abs(h)) / FRACUNIT);
+
+	if (h >= viewheight)
+		h = viewheight;
+
+	while (y < h)
+	{
+		topleft[x + y * vid.width] = pixel;
+		y++;
+	}
+}
+
+static void
+draw_bbox_col
+(		struct bbox_config * bb,
+		int p,
+		fixed_t tx,
+		fixed_t ty)
+{
+	struct bbox_col *col = &bb->col[p];
+
+	fixed_t xscale = FixedDiv(projection, ty);
+	fixed_t yscale = FixedDiv(projectiony, ty);
+
+	col->x = (centerxfrac + FixedMul(tx, xscale)) / FRACUNIT;
+	col->y = (centeryfrac - FixedMul(bb->tz, yscale));
+	col->h = FixedMul(bb->height, yscale);
+
+	// Using this function is TOO EASY!
+	V_DrawFill(
+			viewwindowx + col->x,
+			viewwindowy + col->y / FRACUNIT, 1,
+			col->h / FRACUNIT, V_NOSCALESTART | bb->color);
+}
+
+static void
+draw_bbox_row
+(		struct bbox_config * bb,
+		int p1,
+		int p2)
+{
+	struct bbox_col
+		*a = &bb->col[p1],
+		*b = &bb->col[p2];
+
+	INT32 x1, x2; // left, right
+	INT32 dx; // width
+
+	fixed_t y1, y2; // top, bottom
+	fixed_t s1, s2; // top and bottom increment
+
+	if (a->x > b->x)
+	{
+		struct bbox_col *c = a;
+		a = b;
+		b = c;
+	}
+
+	x1 = a->x;
+	x2 = b->x;
+
+	if (x2 >= viewwidth)
+		x2 = viewwidth - 1;
+
+	if (x1 == x2 || x1 >= viewwidth || x2 < 0)
+		return;
+
+	dx = x2 - x1;
+
+	y1 = a->y;
+	y2 = b->y;
+	s1 = (y2 - y1) / dx;
+
+	y2 = y1 + a->h;
+	s2 = ((b->y + b->h) - y2) / dx;
+
+	// FixedCeil needs a minimum!!! :D :D
+
+	if (s1 == 0)
+		s1 = 1;
+
+	if (s2 == 0)
+		s2 = 1;
+
+	if (x1 < 0)
+	{
+		y1 -= x1 * s1;
+		y2 -= x1 * s2;
+		x1 = 0;
+	}
+
+	while (x1 < x2)
+	{
+		raster_bbox_seg(x1, y1, s1, bb->color);
+		raster_bbox_seg(x1, y2, s2, bb->color);
+
+		y1 += s1;
+		y2 += s2;
+
+		x1++;
+	}
+}
+
+static UINT8
+get_bbox_color (mobj_t *thing)
+{
+	UINT32 flags = thing->flags;
+
+	if (thing->player)
+		return 255; // 0FF
+
+	if (flags & (MF_NOCLIPTHING))
+		return 7; // BFBFBF
+
+	if (flags & (MF_BOSS|MF_MISSILE|MF_ENEMY|MF_PAIN))
+		return 35; // F00
+
+	if (flags & (MF_SPECIAL|MF_MONITOR))
+		return 73; // FF0
+
+	if (flags & (MF_NOCLIP))
+		return 152; // 00F
+
+	return 0; // FFF
+}
+
+void R_DrawThingBoundingBox(mobj_t *thing)
+{
+	fixed_t rs, rc; // radius offsets
+	fixed_t gx, gy; // origin
+	fixed_t tx, ty; // translated coordinates
+
+	struct bbox_config bb = {0};
+
+	rs = FixedMul(thing->radius, viewsin);
+	rc = FixedMul(thing->radius, viewcos);
+
+	gx = thing->x - viewx;
+	gy = thing->y - viewy;
+
+	tx = FixedMul(gx, viewsin) - FixedMul(gy, viewcos);
+	ty = FixedMul(gx, viewcos) + FixedMul(gy, viewsin);
+
+	bb.height = thing->height;
+	bb.tz = (thing->z + bb.height) - viewz;
+	bb.color = get_bbox_color(thing);
+
+	// 1--3
+	// |  |
+	// 0--2
+
+	// left
+
+	tx -= rs;
+	ty -= rc;
+
+	draw_bbox_col(&bb, 0, tx + rc, ty - rs); // bottom
+	draw_bbox_col(&bb, 1, tx - rc, ty + rs); // top
+
+	// right
+
+	tx += rs + rs;
+	ty += rc + rc;
+
+	draw_bbox_col(&bb, 2, tx + rc, ty - rs); // bottom
+	draw_bbox_col(&bb, 3, tx - rc, ty + rs); // top
+
+	// connect all four columns
+
+	draw_bbox_row(&bb, 0, 1);
+	draw_bbox_row(&bb, 1, 3);
+	draw_bbox_row(&bb, 3, 2);
+	draw_bbox_row(&bb, 2, 0);
+}
+
+static boolean is_tangible (mobj_t *thing)
+{
+	// These objects can never touch another
+	if (thing->flags & (MF_NOCLIPTHING))
+	{
+		return false;
+	}
+
+	// These objects probably do nothing! :D
+	if ((thing->flags & (MF_SPECIAL|MF_SOLID|MF_SHOOTABLE
+					|MF_PUSHABLE|MF_BOSS|MF_MISSILE|MF_SPRING
+					|MF_BOUNCE|MF_MONITOR|MF_FIRE|MF_ENEMY
+					|MF_PAIN|MF_STICKY
+					|MF_GRENADEBOUNCE)) == 0U)
+	{
+		return false;
+	}
+
+	return true;
+}
+
+boolean R_ThingBoundingBoxVisible(mobj_t *thing)
+{
+	INT32 cvmode = cv_renderhitbox.value;
+
+	switch (cvmode)
+	{
+		case RENDERHITBOX_OFF:
+			return false;
+
+		case RENDERHITBOX_ALL:
+			return true;
+
+		case RENDERHITBOX_INTANGIBLE:
+			return !is_tangible(thing);
+
+		case RENDERHITBOX_TANGIBLE:
+			// Exclude rings from here, lots of them!
+			if (thing->type == MT_RING)
+			{
+				return false;
+			}
+
+			return is_tangible(thing);
+
+		case RENDERHITBOX_RINGS:
+			return (thing->type == MT_RING);
+
+		default:
+			return false;
+	}
+}
diff --git a/src/r_things.c b/src/r_things.c
index fed873fd6..65047176d 100644
--- a/src/r_things.c
+++ b/src/r_things.c
@@ -2939,6 +2939,14 @@ static void R_DrawSprite(vissprite_t *spr)
 		R_DrawFloorSplat(spr);
 	else
 		R_DrawVisSprite(spr);
+
+	if (R_ThingBoundingBoxVisible(spr->mobj))
+	{
+		// fuck you fuck you fuck you FUCK YOU
+		// (shadows are linked to their mobj)
+		if (!(spr->cut & SC_SHADOW))
+			R_DrawThingBoundingBox(spr->mobj);
+	}
 }
 
 // Special drawer for precipitation sprites Tails 08-18-2002
diff --git a/src/r_things.h b/src/r_things.h
index 35eeb9ce1..4ba649c30 100644
--- a/src/r_things.h
+++ b/src/r_things.h
@@ -66,6 +66,9 @@ void R_AddSprites(sector_t *sec, INT32 lightlevel);
 void R_InitSprites(void);
 void R_ClearSprites(void);
 
+boolean R_ThingBoundingBoxVisible(mobj_t *thing);
+void R_DrawThingBoundingBox(mobj_t *thing);
+
 boolean R_ThingVisible (mobj_t *thing);
 
 boolean R_ThingVisibleWithinDist (mobj_t *thing,
diff --git a/src/screen.h b/src/screen.h
index add048b25..5a69be659 100644
--- a/src/screen.h
+++ b/src/screen.h
@@ -199,7 +199,7 @@ extern CV_PossibleValue_t cv_renderer_t[];
 extern INT32 scr_bpp;
 extern UINT8 *scr_borderpatch; // patch used to fill the view borders
 
-extern consvar_t cv_scr_width, cv_scr_height, cv_scr_depth, cv_renderview, cv_renderer, cv_fullscreen;
+extern consvar_t cv_scr_width, cv_scr_height, cv_scr_depth, cv_renderview, cv_renderer, cv_renderhitbox, cv_fullscreen;
 // wait for page flipping to end or not
 extern consvar_t cv_vidwait;
 extern consvar_t cv_timescale;