diff --git a/src/am_map.cpp b/src/am_map.cpp
index f7f140f4d..fad6a13ac 100644
--- a/src/am_map.cpp
+++ b/src/am_map.cpp
@@ -1898,6 +1898,7 @@ void AM_drawSubsectors()
 	double scalex, scaley;
 	double originx, originy;
 	FDynamicColormap *colormap;
+	PalEntry flatcolor;
 	mpoint_t originpt;
 
 	screen->StartSimplePolys();
@@ -1941,6 +1942,7 @@ void AM_drawSubsectors()
 		colormap = sec->ColorMap;
 
 		FTextureID maptex = sec->GetTexture(sector_t::floor);
+		flatcolor = sec->SpecialColors[sector_t::floor];
 
 		scalex = sec->GetXScale(sector_t::floor);
 		scaley = sec->GetYScale(sector_t::floor);
@@ -1989,6 +1991,7 @@ void AM_drawSubsectors()
 				if (roverz < cmpz)
 				{
 					maptex = *(rover->top.texture);
+					flatcolor = *(rover->top.flatcolor);
 					floorplane = rover->top.plane;
 					sector_t *model = rover->top.model;
 					int selector = (rover->flags & FF_INVERTPLANES) ? sector_t::floor : sector_t::ceiling;
@@ -2049,6 +2052,7 @@ void AM_drawSubsectors()
 				scale / scaley,
 				rotation,
 				colormap,
+				flatcolor,
 				floorlight,
 				f_y + f_h
 				);
diff --git a/src/fragglescript/t_func.cpp b/src/fragglescript/t_func.cpp
index 1ffd34fad..59c82c15c 100644
--- a/src/fragglescript/t_func.cpp
+++ b/src/fragglescript/t_func.cpp
@@ -3875,7 +3875,7 @@ void FParser::SF_SetColor(void)
 			color.r=intvalue(t_argv[1]);
 			color.g=intvalue(t_argv[2]);
 			color.b=intvalue(t_argv[3]);
-			color.a = (DFraggleThinker::ActiveThinker->setcolormaterial) ? 255 : 0;
+			color.a = 0;
 		}
 		else return;
 
@@ -3891,7 +3891,7 @@ void FParser::SF_SetColor(void)
 				for (int j = 0; j < 4; j++) level.sectors[i].SpecialColors[j] = color;
 				// simulates 'nocoloredspritelighting' settings.
 				int v = (color.r + color.g + color.b) / 3;
-				level.sectors[i].SpecialColors[4] = (255 + v + v) / 3;
+				level.sectors[i].SpecialColors[sector_t::sprites] = (255 + v + v) / 3;
 			}
 		}
 	}
diff --git a/src/gl/renderer/gl_2ddrawer.cpp b/src/gl/renderer/gl_2ddrawer.cpp
index ba78634a3..1907edeef 100644
--- a/src/gl/renderer/gl_2ddrawer.cpp
+++ b/src/gl/renderer/gl_2ddrawer.cpp
@@ -174,7 +174,7 @@ void F2DDrawer::AddTexture(FTexture *img, DrawParms &parms)
 
 void F2DDrawer::AddPoly(FTexture *texture, FVector2 *points, int npoints,
 		double originx, double originy, double scalex, double scaley,
-		DAngle rotation, FDynamicColormap *colormap, int lightlevel)
+		DAngle rotation, FDynamicColormap *colormap, PalEntry flatcolor, int lightlevel)
 {
 	FMaterial *gltexture = FMaterial::ValidateTexture(texture, false);
 
@@ -191,6 +191,7 @@ void F2DDrawer::AddPoly(FTexture *texture, FVector2 *points, int npoints,
 	poly.mLightLevel = lightlevel;
 	poly.mVertCount = npoints;
 	poly.mVertIndex = (int)mVertices.Reserve(npoints);
+	poly.mFlatColor = flatcolor;
 
 	bool dorotate = rotation != 0;
 
@@ -438,8 +439,10 @@ void F2DDrawer::Draw()
 			cm = dsp->mColormap;
 			gl_SetColor(dsp->mLightLevel, 0, cm, 1.f);
 			gl_RenderState.SetMaterial(dsp->mTexture, CLAMP_NONE, 0, -1, false);
+			gl_RenderState.SetObjectColor(dsp->mFlatColor|0xff000000);
 			gl_RenderState.Apply();
 			glDrawArrays(GL_TRIANGLE_FAN, dsp->mVertIndex, dsp->mVertCount);
+			gl_RenderState.SetObjectColor(0xffffffff);
 			break;
 		}
 
diff --git a/src/gl/renderer/gl_2ddrawer.h b/src/gl/renderer/gl_2ddrawer.h
index 8c27f13d8..61f3153d3 100644
--- a/src/gl/renderer/gl_2ddrawer.h
+++ b/src/gl/renderer/gl_2ddrawer.h
@@ -45,6 +45,7 @@ class F2DDrawer : public FSimpleVertexBuffer
 		FMaterial *mTexture;
 		int mLightLevel;
 		FDynamicColormap *mColormap;
+		PalEntry mFlatColor;
 	};
 
 	TArray<FSimpleVertex> mVertices;
@@ -61,7 +62,7 @@ public:
 	
 	void AddPoly(FTexture *texture, FVector2 *points, int npoints,
 		double originx, double originy, double scalex, double scaley,
-		DAngle rotation, FDynamicColormap *colormap, int lightlevel);
+		DAngle rotation, FDynamicColormap *colormap, PalEntry flatcolor, int lightlevel);
 		
 	void AddLine(int x1, int y1, int x2, int y2, int palcolor, uint32 color);
 	void AddPixel(int x1, int y1, int palcolor, uint32 color);
diff --git a/src/gl/renderer/gl_renderer.h b/src/gl/renderer/gl_renderer.h
index 869b46d2d..95739e86d 100644
--- a/src/gl/renderer/gl_renderer.h
+++ b/src/gl/renderer/gl_renderer.h
@@ -216,7 +216,7 @@ public:
 
 	void FillSimplePoly(FTexture *texture, FVector2 *points, int npoints,
 		double originx, double originy, double scalex, double scaley,
-		DAngle rotation, FDynamicColormap *colormap, int lightlevel, int bottomclip);
+		DAngle rotation, FDynamicColormap *colormap, PalEntry flatcolor, int lightlevel, int bottomclip);
 
 	int PTM_BestColor (const uint32 *pal_in, int r, int g, int b, int first, int num);
 
diff --git a/src/gl/renderer/gl_renderstate.cpp b/src/gl/renderer/gl_renderstate.cpp
index d70eb5166..c3c884013 100644
--- a/src/gl/renderer/gl_renderstate.cpp
+++ b/src/gl/renderer/gl_renderstate.cpp
@@ -169,8 +169,6 @@ bool FRenderState::ApplyShader()
 	{
 		activeShader->muGlowTopColor.Set(mGlowTop.vec);
 		activeShader->muGlowBottomColor.Set(mGlowBottom.vec);
-		activeShader->muGlowTopPlane.Set(mGlowTopPlane.vec);
-		activeShader->muGlowBottomPlane.Set(mGlowBottomPlane.vec);
 		activeShader->currentglowstate = 1;
 	}
 	else if (activeShader->currentglowstate)
@@ -178,10 +176,13 @@ bool FRenderState::ApplyShader()
 		// if glowing is on, disable it.
 		activeShader->muGlowTopColor.Set(nulvec);
 		activeShader->muGlowBottomColor.Set(nulvec);
-		activeShader->muGlowTopPlane.Set(nulvec);
-		activeShader->muGlowBottomPlane.Set(nulvec);
 		activeShader->currentglowstate = 0;
 	}
+	if (mGlowEnabled || mObjectColor2.a != 0)
+	{
+		activeShader->muGlowTopPlane.Set(mGlowTopPlane.vec);
+		activeShader->muGlowBottomPlane.Set(mGlowBottomPlane.vec);
+	}
 
 	if (mSplitEnabled)
 	{
diff --git a/src/gl/scene/gl_flats.cpp b/src/gl/scene/gl_flats.cpp
index c4296c50d..1ed0fecfa 100644
--- a/src/gl/scene/gl_flats.cpp
+++ b/src/gl/scene/gl_flats.cpp
@@ -379,6 +379,7 @@ void GLFlat::Draw(int pass, bool trans)	// trans only has meaning for GLPASS_LIG
 	case GLPASS_ALL:			// Same, but also creates the dynlight data.
 		gl_SetColor(lightlevel, rel, Colormap,1.0f);
 		gl_SetFog(lightlevel, rel, &Colormap, false);
+		gl_RenderState.SetObjectColor(FlatColor | 0xff000000);
 		if (sector->special != GLSector_Skybox)
 		{
 			gl_RenderState.SetMaterial(gltexture, CLAMP_NONE, 0, -1, false);
@@ -391,6 +392,7 @@ void GLFlat::Draw(int pass, bool trans)	// trans only has meaning for GLPASS_LIG
 			gl_RenderState.SetMaterial(gltexture, CLAMP_XY, 0, -1, false);
 			DrawSkyboxSector(pass, (pass == GLPASS_ALL || dynlightindex > -1));
 		}
+		gl_RenderState.SetObjectColor(0xffffffff);
 		break;
 
 	case GLPASS_LIGHTSONLY:
@@ -404,7 +406,8 @@ void GLFlat::Draw(int pass, bool trans)	// trans only has meaning for GLPASS_LIG
 		if (renderstyle==STYLE_Add) gl_RenderState.BlendFunc(GL_SRC_ALPHA, GL_ONE);
 		gl_SetColor(lightlevel, rel, Colormap, alpha);
 		gl_SetFog(lightlevel, rel, &Colormap, false);
-		if (!gltexture)	
+		gl_RenderState.SetObjectColor(FlatColor | 0xff000000);
+		if (!gltexture)
 		{
 			gl_RenderState.AlphaFunc(GL_GEQUAL, 0.f);
 			gl_RenderState.EnableTexture(false);
@@ -421,6 +424,7 @@ void GLFlat::Draw(int pass, bool trans)	// trans only has meaning for GLPASS_LIG
 			gl_RenderState.EnableTextureMatrix(false);
 		}
 		if (renderstyle==STYLE_Add) gl_RenderState.BlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+		gl_RenderState.SetObjectColor(0xffffffff);
 		break;
 
 	case GLPASS_LIGHTTEX:
@@ -546,8 +550,16 @@ void GLFlat::SetFrom3DFloor(F3DFloor *rover, bool top, bool underside)
 	lightlist_t *light = P_GetPlaneLight(sector, plane.plane, underside);
 	lightlevel = gl_ClampLight(*light->p_lightlevel);
 	
-	if (rover->flags & FF_FOG) Colormap.LightColor = (light->extra_colormap)->Fade;
-	else Colormap.CopyFrom3DLight(light);
+	if (rover->flags & FF_FOG)
+	{
+		Colormap.LightColor = (light->extra_colormap)->Fade;
+		FlatColor = 0xffffffff;
+	}
+	else
+	{
+		Colormap.CopyFrom3DLight(light);
+		FlatColor = *plane.flatcolor;
+	}
 
 
 	alpha = rover->alpha/255.0f;
@@ -604,6 +616,7 @@ void GLFlat::ProcessSector(sector_t * frontsector)
 
 		lightlevel = gl_ClampLight(frontsector->GetFloorLight());
 		Colormap = frontsector->ColorMap;
+		FlatColor = frontsector->SpecialColors[sector_t::floor];
 		port = frontsector->ValidatePortal(sector_t::floor);
 		if ((stack = (port != NULL)))
 		{
@@ -663,6 +676,7 @@ void GLFlat::ProcessSector(sector_t * frontsector)
 
 		lightlevel = gl_ClampLight(frontsector->GetCeilingLight());
 		Colormap = frontsector->ColorMap;
+		FlatColor = frontsector->SpecialColors[sector_t::ceiling];
 		port = frontsector->ValidatePortal(sector_t::ceiling);
 		if ((stack = (port != NULL)))
 		{
diff --git a/src/gl/scene/gl_wall.h b/src/gl/scene/gl_wall.h
index 902517a9b..151a5ef71 100644
--- a/src/gl/scene/gl_wall.h
+++ b/src/gl/scene/gl_wall.h
@@ -301,6 +301,7 @@ public:
 	FMaterial *gltexture;
 
 	FColormap Colormap;	// light and fog
+	PalEntry FlatColor;
 	ERenderStyle renderstyle;
 
 	float alpha;
diff --git a/src/gl/scene/gl_walls_draw.cpp b/src/gl/scene/gl_walls_draw.cpp
index 7849114ff..05461fd55 100644
--- a/src/gl/scene/gl_walls_draw.cpp
+++ b/src/gl/scene/gl_walls_draw.cpp
@@ -24,6 +24,7 @@
 #include "p_local.h"
 #include "p_lnspec.h"
 #include "a_sharedglobal.h"
+#include "g_levellocals.h"
 #include "gl/gl_functions.h"
 
 #include "gl/system/gl_interface.h"
@@ -326,9 +327,9 @@ void GLWall::RenderTextured(int rflags)
 	if (flags & GLWF_GLOW)
 	{
 		gl_RenderState.EnableGlow(true);
-		gl_RenderState.SetGlowPlanes(topplane, bottomplane);
 		gl_RenderState.SetGlowParams(topglowcolor, bottomglowcolor);
 	}
+	gl_RenderState.SetGlowPlanes(topplane, bottomplane);
 	gl_RenderState.SetMaterial(gltexture, flags & 3, 0, -1, false);
 
 	if (type == RENDERWALL_M2SNF)
@@ -339,12 +340,14 @@ void GLWall::RenderTextured(int rflags)
 		}
 		gl_SetFog(255, 0, NULL, false);
 	}
+	gl_RenderState.SetObjectColor(seg->frontsector->SpecialColors[sector_t::walltop] | 0xff000000);
+	gl_RenderState.SetObjectColor2(seg->frontsector->SpecialColors[sector_t::wallbottom] | 0xff000000);
 
 	float absalpha = fabsf(alpha);
 	if (lightlist == NULL)
 	{
-		gl_SetColor(lightlevel, rel, Colormap, absalpha);
 		if (type != RENDERWALL_M2SNF) gl_SetFog(lightlevel, rel, &Colormap, RenderStyle == STYLE_Add);
+		gl_SetColor((seg->frontsector->MoreFlags & SECF_SPECIALCOLORSABSOLUTE)? 255 : lightlevel, rel, Colormap, absalpha);
 		RenderWall(rflags);
 	}
 	else
@@ -364,7 +367,7 @@ void GLWall::RenderTextured(int rflags)
 				FColormap thiscm;
 				thiscm.FadeColor = Colormap.FadeColor;
 				thiscm.CopyFrom3DLight(&(*lightlist)[i]);
-				gl_SetColor(thisll, rel, thiscm, absalpha);
+				gl_SetColor((seg->frontsector->MoreFlags & SECF_SPECIALCOLORSABSOLUTE) ? 255 : thisll, rel, thiscm, absalpha);
 				if (type != RENDERWALL_M2SNF) gl_SetFog(thisll, rel, &thiscm, RenderStyle == STYLE_Add);
 				gl_RenderState.SetSplitPlanes((*lightlist)[i].plane, lowplane);
 				RenderWall(rflags);
@@ -374,6 +377,8 @@ void GLWall::RenderTextured(int rflags)
 
 		gl_RenderState.EnableSplit(false);
 	}
+	gl_RenderState.SetObjectColor(0xffffffff);
+	gl_RenderState.SetObjectColor2(0);
 	gl_RenderState.SetTextureMode(tmode);
 	gl_RenderState.EnableGlow(false);
 }
diff --git a/src/gl/system/gl_framebuffer.cpp b/src/gl/system/gl_framebuffer.cpp
index 6d4fdcff8..1a4582d80 100644
--- a/src/gl/system/gl_framebuffer.cpp
+++ b/src/gl/system/gl_framebuffer.cpp
@@ -470,11 +470,11 @@ void OpenGLFrameBuffer::Clear(int left, int top, int right, int bottom, int palc
 
 void OpenGLFrameBuffer::FillSimplePoly(FTexture *texture, FVector2 *points, int npoints,
 	double originx, double originy, double scalex, double scaley,
-	DAngle rotation, FDynamicColormap *colormap, int lightlevel, int bottomclip)
+	DAngle rotation, FDynamicColormap *colormap, PalEntry flatcolor, int lightlevel, int bottomclip)
 {
 	if (GLRenderer != nullptr && GLRenderer->m2DDrawer != nullptr && npoints >= 3)
 	{
-		GLRenderer->m2DDrawer->AddPoly(texture, points, npoints, originx, originy, scalex, scaley, rotation, colormap, lightlevel);
+		GLRenderer->m2DDrawer->AddPoly(texture, points, npoints, originx, originy, scalex, scaley, rotation, colormap, flatcolor, lightlevel);
 	}
 }
 
diff --git a/src/gl/system/gl_framebuffer.h b/src/gl/system/gl_framebuffer.h
index 27c3d1cf9..0eb289ffe 100644
--- a/src/gl/system/gl_framebuffer.h
+++ b/src/gl/system/gl_framebuffer.h
@@ -71,7 +71,7 @@ public:
 
 	void FillSimplePoly(FTexture *tex, FVector2 *points, int npoints,
 		double originx, double originy, double scalex, double scaley,
-		DAngle rotation, FDynamicColormap *colormap, int lightlevel, int bottomclip);
+		DAngle rotation, FDynamicColormap *colormap, PalEntry flatcolor, int lightlevel, int bottomclip);
 
 	FNativePalette *CreatePalette(FRemapTable *remap);
 
diff --git a/src/p_3dfloors.cpp b/src/p_3dfloors.cpp
index 102ed57b0..77e34adba 100644
--- a/src/p_3dfloors.cpp
+++ b/src/p_3dfloors.cpp
@@ -136,12 +136,14 @@ static void P_Add3DFloor(sector_t* sec, sector_t* sec2, line_t* master, int flag
 	{
 		ffloor->bottom.plane = &sec2->floorplane;
 		ffloor->bottom.texture = &sec2->planes[sector_t::floor].Texture;
+		ffloor->bottom.flatcolor = &sec2->SpecialColors[sector_t::floor];
 		ffloor->bottom.isceiling = sector_t::floor;
 	}
 	else 
 	{
 		ffloor->bottom.plane = &sec2->ceilingplane;
 		ffloor->bottom.texture = &sec2->planes[sector_t::ceiling].Texture;
+		ffloor->bottom.flatcolor = &sec2->SpecialColors[sector_t::ceiling];
 		ffloor->bottom.isceiling = sector_t::ceiling;
 	}
 	
@@ -149,6 +151,7 @@ static void P_Add3DFloor(sector_t* sec, sector_t* sec2, line_t* master, int flag
 	{
 		ffloor->top.plane = &sec2->ceilingplane;
 		ffloor->top.texture = &sec2->planes[sector_t::ceiling].Texture;
+		ffloor->top.flatcolor = &sec2->SpecialColors[sector_t::ceiling];
 		ffloor->toplightlevel = &sec2->lightlevel;
 		ffloor->top.isceiling = sector_t::ceiling;
 	}
@@ -156,6 +159,7 @@ static void P_Add3DFloor(sector_t* sec, sector_t* sec2, line_t* master, int flag
 	{
 		ffloor->top.plane = &sec->floorplane;
 		ffloor->top.texture = &sec2->planes[sector_t::floor].Texture;
+		ffloor->top.flatcolor = &sec2->SpecialColors[sector_t::floor];
 		ffloor->toplightlevel = &sec->lightlevel;
 		ffloor->top.isceiling = sector_t::floor;
 		ffloor->top.model = sec;
@@ -165,10 +169,7 @@ static void P_Add3DFloor(sector_t* sec, sector_t* sec2, line_t* master, int flag
 	if (flags&FF_INVERTSECTOR)
 	{
 		// switch the planes
-		F3DFloor::planeref sp = ffloor->top;
-
-		ffloor->top=ffloor->bottom;
-		ffloor->bottom=sp;
+		std::swap(ffloor->top, ffloor->bottom);
 
 		if (flags&FF_SWIMMABLE)
 		{
@@ -192,11 +193,10 @@ static void P_Add3DFloor(sector_t* sec, sector_t* sec2, line_t* master, int flag
 		ffloor->flags &= ~FF_ADDITIVETRANS;
 	}
 
-	if(flags & FF_THISINSIDE) {
+	if(flags & FF_THISINSIDE) 
+	{
 		// switch the planes
-		F3DFloor::planeref sp = ffloor->top;
-		ffloor->top=ffloor->bottom;
-		ffloor->bottom=sp;
+		std::swap(ffloor->top, ffloor->bottom);
 	}
 
 	sec->e->XFloor.ffloors.Push(ffloor);
diff --git a/src/p_3dfloors.h b/src/p_3dfloors.h
index fc784c55c..75b8656e4 100644
--- a/src/p_3dfloors.h
+++ b/src/p_3dfloors.h
@@ -69,6 +69,7 @@ struct F3DFloor
 		secplane_t *	plane;
 		const FTextureID *	texture;
 		sector_t *		model;
+		PalEntry *		flatcolor;
 		int				isceiling;
 		int				vindex;
 		bool			copied;
diff --git a/src/v_draw.cpp b/src/v_draw.cpp
index 3d4954ed2..9db885efb 100644
--- a/src/v_draw.cpp
+++ b/src/v_draw.cpp
@@ -1272,7 +1272,7 @@ void DCanvas::FinishSimplePolys()
 
 void DCanvas::FillSimplePoly(FTexture *tex, FVector2 *points, int npoints,
 	double originx, double originy, double scalex, double scaley, DAngle rotation,
-	FDynamicColormap *colormap, int lightlevel, int bottomclip)
+	FDynamicColormap *colormap, PalEntry flatcolor, int lightlevel, int bottomclip)
 {
 #ifndef NO_SWRENDER
 	using namespace swrenderer;
diff --git a/src/v_video.h b/src/v_video.h
index 57d15869c..e9bb1f6a4 100644
--- a/src/v_video.h
+++ b/src/v_video.h
@@ -224,7 +224,7 @@ public:
 	// Fill a simple polygon with a texture
 	virtual void FillSimplePoly(FTexture *tex, FVector2 *points, int npoints,
 		double originx, double originy, double scalex, double scaley, DAngle rotation,
-		struct FDynamicColormap *colormap, int lightlevel, int bottomclip);
+		struct FDynamicColormap *colormap, PalEntry flatcolor, int lightlevel, int bottomclip);
 
 	// Set an area to a specified color
 	virtual void Clear (int left, int top, int right, int bottom, int palcolor, uint32 color);
diff --git a/src/win32/fb_d3d9.cpp b/src/win32/fb_d3d9.cpp
index 026bbc63b..4d758783e 100644
--- a/src/win32/fb_d3d9.cpp
+++ b/src/win32/fb_d3d9.cpp
@@ -3092,7 +3092,7 @@ void D3DFB::FlatFill(int left, int top, int right, int bottom, FTexture *src, bo
 
 void D3DFB::FillSimplePoly(FTexture *texture, FVector2 *points, int npoints,
 	double originx, double originy, double scalex, double scaley,
-	DAngle rotation, FDynamicColormap *colormap, int lightlevel, int bottomclip)
+	DAngle rotation, FDynamicColormap *colormap, PalEntry flatcolor, int lightlevel, int bottomclip)
 {
 	// Use an equation similar to player sprites to determine shade
 	double fadelevel = clamp((LIGHT2SHADE(lightlevel)/65536. - 12) / NUMCOLORMAPS, 0.0, 1.0);
@@ -3113,7 +3113,7 @@ void D3DFB::FillSimplePoly(FTexture *texture, FVector2 *points, int npoints,
 	}
 	if (In2D < 2)
 	{
-		Super::FillSimplePoly(texture, points, npoints, originx, originy, scalex, scaley, rotation, colormap, lightlevel, bottomclip);
+		Super::FillSimplePoly(texture, points, npoints, originx, originy, scalex, scaley, rotation, colormap, flatcolor, lightlevel, bottomclip);
 		return;
 	}
 	if (!InScene)
diff --git a/src/win32/win32iface.h b/src/win32/win32iface.h
index b5262089b..a92672ad7 100644
--- a/src/win32/win32iface.h
+++ b/src/win32/win32iface.h
@@ -265,7 +265,7 @@ public:
 	void DrawPixel(int x, int y, int palcolor, uint32 rgbcolor);
 	void FillSimplePoly(FTexture *tex, FVector2 *points, int npoints,
 		double originx, double originy, double scalex, double scaley,
-		DAngle rotation, FDynamicColormap *colormap, int lightlevel, int bottomclip) override;
+		DAngle rotation, FDynamicColormap *colormap, PalEntry flatcolor, int lightlevel, int bottomclip) override;
 	bool WipeStartScreen(int type);
 	void WipeEndScreen();
 	bool WipeDo(int ticks);
diff --git a/wadsrc/static/shaders/glsl/main.vp b/wadsrc/static/shaders/glsl/main.vp
index f4937ab66..f66ee7b04 100644
--- a/wadsrc/static/shaders/glsl/main.vp
+++ b/wadsrc/static/shaders/glsl/main.vp
@@ -54,10 +54,7 @@ void main()
 		float bottomatpoint = -((uGlowBottomPlane.w + uGlowBottomPlane.x * worldcoord.x + uGlowBottomPlane.y * worldcoord.z) * uGlowBottomPlane.z);
 		glowdist.x = topatpoint - worldcoord.y;
 		glowdist.y = worldcoord.y - bottomatpoint;
-		glowdist.z = glowdist.x / (topatpoint - bottomatpoint);
-		
-
-		return (uGlowTopPlane.w + normal.X*v->fX() + normal.Y*v->fY()) * negiC;
+		glowdist.z = clamp(glowdist.x / (topatpoint - bottomatpoint), 0.0, 1.0);
 		
 		if (uSplitBottomPlane.z != 0.0)
 		{