diff --git a/src/rendering/hwrenderer/scene/hw_bsp.cpp b/src/rendering/hwrenderer/scene/hw_bsp.cpp
index 4ff193e1d..512e3b1e0 100644
--- a/src/rendering/hwrenderer/scene/hw_bsp.cpp
+++ b/src/rendering/hwrenderer/scene/hw_bsp.cpp
@@ -266,6 +266,8 @@ void HWDrawInfo::UnclipSubsector(subsector_t *sub)
 
 void HWDrawInfo::AddLine (seg_t *seg, bool portalclip)
 {
+	const bool doOob = Viewpoint.bDoOob;
+
 #ifdef _DEBUG
 	if (seg->linedef && seg->linedef->Index() == 38)
 	{
@@ -289,7 +291,7 @@ void HWDrawInfo::AddLine (seg_t *seg, bool portalclip)
 	angle_t endAngleR = 0;
 	angle_t paddingR = 0x00200000; // Make radar clipping more aggressive (reveal less)
 
-	if(Viewpoint.IsAllowedOoB() && r_radarclipper && !(Level->flags3 & LEVEL3_NOFOGOFWAR))
+	if(doOob && r_radarclipper && !(Level->flags3 & LEVEL3_NOFOGOFWAR))
 	{
 		startAngleR = clipperr.PointToPseudoAngle(seg->v2->fX(), seg->v2->fY());
 		endAngleR = clipperr.PointToPseudoAngle(seg->v1->fX(), seg->v1->fY());
@@ -317,11 +319,11 @@ void HWDrawInfo::AddLine (seg_t *seg, bool portalclip)
 	{
 		if (!(currentsubsector->flags & SSECMF_DRAWN))
 		{
-			if (clipper.SafeCheckRange(startAngle, endAngle) && !Viewpoint.IsAllowedOoB())
+			if (clipper.SafeCheckRange(startAngle, endAngle) && !doOob)
 			{
 			  currentsubsector->flags |= SSECMF_DRAWN;
 			}
-			if (Viewpoint.IsAllowedOoB() && (r_radarclipper && !(Level->flags3 & LEVEL3_NOFOGOFWAR)) && clipperr.SafeCheckRange(startAngleR, endAngleR))
+			if (doOob && (r_radarclipper && !(Level->flags3 & LEVEL3_NOFOGOFWAR)) && clipperr.SafeCheckRange(startAngleR, endAngleR))
 			{
 			  currentsubsector->flags |= SSECMF_DRAWN;
 			}
@@ -334,14 +336,14 @@ void HWDrawInfo::AddLine (seg_t *seg, bool portalclip)
 		return;
 	}
 
-	if (!Viewpoint.IsAllowedOoB() || (!r_radarclipper || (Level->flags3 & LEVEL3_NOFOGOFWAR) || clipperr.SafeCheckRange(startAngleR, endAngleR)))
+	if (!doOob || (!r_radarclipper || (Level->flags3 & LEVEL3_NOFOGOFWAR) || clipperr.SafeCheckRange(startAngleR, endAngleR)))
 		currentsubsector->flags |= SSECMF_DRAWN;
 
 	uint8_t ispoly = uint8_t(seg->sidedef->Flags & WALLF_POLYOBJ);
 
 	if (!seg->backsector)
 	{
-		if(!Viewpoint.IsAllowedOoB())
+		if(!doOob)
 			if (!(seg->sidedef->Flags & WALLF_DITHERTRANS_MID)) clipper.SafeAddClipRange(startAngle, endAngle);
 	}
 	else if (!ispoly)	// Two-sided polyobjects never obstruct the view
@@ -369,7 +371,7 @@ void HWDrawInfo::AddLine (seg_t *seg, bool portalclip)
 
 			if (hw_CheckClip(seg->sidedef, currentsector, backsector))
 			{
-				if(!Viewpoint.IsAllowedOoB() && !(seg->sidedef->Flags & WALLF_DITHERTRANS_MID))
+				if(!doOob && !(seg->sidedef->Flags & WALLF_DITHERTRANS_MID))
 					clipper.SafeAddClipRange(startAngle, endAngle);
 			}
 		}
@@ -578,7 +580,7 @@ void HWDrawInfo::RenderThings(subsector_t * sub, sector_t * sector)
 		if (thing->validcount == validcount) continue;
 		thing->validcount = validcount;
 
-		if(Viewpoint.IsAllowedOoB() && thing->Sector->isSecret() && thing->Sector->wasSecret() && !r_radarclipper) continue; // This covers things that are touching non-secret sectors
+		if(Viewpoint.bDoOob && thing->Sector->isSecret() && thing->Sector->wasSecret() && !r_radarclipper) continue; // This covers things that are touching non-secret sectors
 		FIntCVar *cvar = thing->GetInfo()->distancecheck;
 		if (cvar != nullptr && *cvar >= 0)
 		{
@@ -683,6 +685,7 @@ void HWDrawInfo::RenderParticles(subsector_t *sub, sector_t *front)
 
 void HWDrawInfo::DoSubsector(subsector_t * sub)
 {
+	const bool doOob = Viewpoint.bDoOob;
 	sector_t * sector;
 	sector_t * fakesector;
 	
@@ -711,10 +714,10 @@ void HWDrawInfo::DoSubsector(subsector_t * sub)
 
 	fakesector=hw_FakeFlat(sector, in_area, false);
 
-	if(Viewpoint.IsAllowedOoB() && sector->isSecret() && sector->wasSecret() && !r_radarclipper) return;
+	if(doOob && sector->isSecret() && sector->wasSecret() && !r_radarclipper) return;
 
 	// cull everything if subsector outside all relevant clippers
-	if (Viewpoint.IsAllowedOoB() && (sub->polys == nullptr))
+	if (doOob && (sub->polys == nullptr))
 	{
 		auto &clipper = *mClipper;
 		auto &clipperv = *vClipper;
@@ -722,11 +725,10 @@ void HWDrawInfo::DoSubsector(subsector_t * sub)
 		int count = sub->numlines;
 		seg_t * seg = sub->firstline;
 		bool anglevisible = false;
-		bool pitchvisible = !(Viewpoint.IsAllowedOoB()); // No vertical clipping if viewpoint is not allowed out of bounds
-		bool radarvisible = !(Viewpoint.IsAllowedOoB()) || !r_radarclipper || (Level->flags3 & LEVEL3_NOFOGOFWAR) || ((sub->flags & SSECMF_DRAWN) && !deathmatch);
-		bool ceilreflect = (mCurrentPortal && strcmp(mCurrentPortal->GetName(), "Planemirror ceiling"));
-		bool floorreflect = (mCurrentPortal && strcmp(mCurrentPortal->GetName(), "Planemirror floor"));
-		double planez = (ceilreflect ? sector->ceilingplane.ZatPoint(Viewpoint.Pos) : sector->floorplane.ZatPoint(Viewpoint.Pos));
+		bool pitchvisible = false;
+		bool radarvisible = !r_radarclipper || (Level->flags3 & LEVEL3_NOFOGOFWAR) || ((sub->flags & SSECMF_DRAWN) && !deathmatch);
+		const int reflect = mCurrentPortal ? mCurrentPortal->GetMirrorSide() : 0; // -1 = ceiling, 1 = floor, 0 = none
+		const double planez = (reflect < 0 ? sector->ceilingplane.ZatPoint(Viewpoint.Pos) : sector->floorplane.ZatPoint(Viewpoint.Pos));
 		angle_t pitchtemp;
 		angle_t pitchmin = ANGLE_90;
 		angle_t pitchmax = 0;
@@ -751,11 +753,11 @@ void HWDrawInfo::DoSubsector(subsector_t * sub)
 				if (!pitchvisible)
 				{
 					pitchmin = clipperv.PointToPseudoPitch(seg->v1->fX(), seg->v1->fY(),
-														   (ceilreflect || floorreflect) ?
+														   (reflect != 0) ?
 														   2 * planez - sector->floorplane.ZatPoint(seg->v1) :
 														   sector->floorplane.ZatPoint(seg->v1));
 					pitchmax = clipperv.PointToPseudoPitch(seg->v1->fX(), seg->v1->fY(),
-														   (ceilreflect || floorreflect) ?
+														   (reflect != 0) ?
 														   2 * planez - sector->ceilingplane.ZatPoint(seg->v1) :
 														   sector->ceilingplane.ZatPoint(seg->v1));
 					pitchvisible |= clipperv.SafeCheckRange(pitchmin, pitchmax);
@@ -764,12 +766,12 @@ void HWDrawInfo::DoSubsector(subsector_t * sub)
 				if (!pitchvisible)
 				{
 					pitchtemp = clipperv.PointToPseudoPitch(seg->v2->fX(), seg->v2->fY(),
-															(ceilreflect || floorreflect) ?
+															(reflect != 0) ?
 															2 * planez - sector->floorplane.ZatPoint(seg->v2) :
 															sector->floorplane.ZatPoint(seg->v2));
 					if (int(pitchmin) > int(pitchtemp)) pitchmin = pitchtemp;
 					pitchtemp = clipperv.PointToPseudoPitch(seg->v2->fX(), seg->v2->fY(),
-															(ceilreflect || floorreflect) ?
+															(reflect != 0) ?
 															2 * planez - sector->ceilingplane.ZatPoint(seg->v2) :
 															sector->ceilingplane.ZatPoint(seg->v2));
 					if (int(pitchmax) < int(pitchtemp)) pitchmax = pitchtemp;
@@ -840,7 +842,7 @@ void HWDrawInfo::DoSubsector(subsector_t * sub)
 				SetupSprite.Unclock();
 			}
 		}
-		if (r_dithertransparency && Viewpoint.IsAllowedOoB() && (RTnum < MAXDITHERACTORS) && mCurrentPortal == nullptr)
+		if (r_dithertransparency && doOob && (RTnum < MAXDITHERACTORS) && mCurrentPortal == nullptr)
 		{
 			// [DVR] Not parallelizable due to variables RTnum and RenderedTargets[]
 			for (auto p = sector->touching_renderthings; p != nullptr; p = p->m_snext)
@@ -974,7 +976,7 @@ void HWDrawInfo::RenderBSPNode (void *node)
 			if (!(no_renderflags[bsp->Index()] & SSRF_SEEN))
 				return;
 		}
-		if (Viewpoint.IsOrtho())
+		if (Viewpoint.bDoOrtho)
 		{
 			if (!vClipper->CheckBoxOrthoPitch(bsp->bbox[side]))
 			{
@@ -991,7 +993,7 @@ void HWDrawInfo::RenderBSPNode (void *node)
 // No need for clipping inside frustum if no fog of war (How is this faster!)
 void HWDrawInfo::RenderOrthoNoFog()
 {
-	if (Viewpoint.IsOrtho() && ((Level->flags3 & LEVEL3_NOFOGOFWAR) || !r_radarclipper))
+	if (Viewpoint.bDoOrtho && ((Level->flags3 & LEVEL3_NOFOGOFWAR) || !r_radarclipper))
 	{
 		double vxdbl = Viewpoint.OffPos.X;
 		double vydbl = Viewpoint.OffPos.Y;
@@ -1017,7 +1019,7 @@ void HWDrawInfo::RenderBSP(void *node, bool drawpsprites)
 	// Give the DrawInfo the viewpoint in fixed point because that's what the nodes are.
 	viewx = FLOAT2FIXED(Viewpoint.Pos.X);
 	viewy = FLOAT2FIXED(Viewpoint.Pos.Y);
-	if (r_radarclipper && !(Level->flags3 & LEVEL3_NOFOGOFWAR) && Viewpoint.IsAllowedOoB())
+	if (r_radarclipper && !(Level->flags3 & LEVEL3_NOFOGOFWAR) && Viewpoint.bDoOob)
 	{
 		viewx = FLOAT2FIXED(Viewpoint.OffPos.X);
 		viewy = FLOAT2FIXED(Viewpoint.OffPos.Y);
@@ -1032,7 +1034,7 @@ void HWDrawInfo::RenderBSP(void *node, bool drawpsprites)
 		auto future = renderPool.push([&](int id) {
 			WorkerThread();
 		});
-		if (Viewpoint.IsOrtho() && ((Level->flags3 & LEVEL3_NOFOGOFWAR) || !r_radarclipper)) RenderOrthoNoFog();
+		if (Viewpoint.bDoOrtho && ((Level->flags3 & LEVEL3_NOFOGOFWAR) || !r_radarclipper)) RenderOrthoNoFog();
 		else RenderBSPNode(node);
 
 		jobQueue.AddJob(RenderJob::TerminateJob, nullptr, nullptr);
@@ -1043,7 +1045,7 @@ void HWDrawInfo::RenderBSP(void *node, bool drawpsprites)
 	}
 	else
 	{
-		if (Viewpoint.IsOrtho() && ((Level->flags3 & LEVEL3_NOFOGOFWAR) || !r_radarclipper)) RenderOrthoNoFog();
+		if (Viewpoint.bDoOrtho && ((Level->flags3 & LEVEL3_NOFOGOFWAR) || !r_radarclipper)) RenderOrthoNoFog();
 		else RenderBSPNode(node);
 		Bsp.Unclock();
 	}
diff --git a/src/rendering/hwrenderer/scene/hw_clipper.cpp b/src/rendering/hwrenderer/scene/hw_clipper.cpp
index 7444af309..4638123c6 100644
--- a/src/rendering/hwrenderer/scene/hw_clipper.cpp
+++ b/src/rendering/hwrenderer/scene/hw_clipper.cpp
@@ -404,7 +404,7 @@ angle_t Clipper::PointToPseudoAngle(double x, double y)
 	{
 		return 0;
 	}
-	else if (!amRadar && viewpoint->IsOrtho())
+	else if (!amRadar && viewpoint->bDoOrtho)
 	{
 		return PointToPseudoOrthoAngle(x, y);
 	}
@@ -431,7 +431,7 @@ angle_t Clipper::PointToPseudoPitch(double x, double y, double z)
 	{
 		return 0;
 	}
-	else if (viewpoint->IsOrtho())
+	else if (viewpoint->bDoOrtho)
 	{
 		return PointToPseudoOrthoPitch(x, y, z);
 	}
@@ -545,7 +545,7 @@ bool Clipper::CheckBox(const float *bspcoord)
 	angle1 = PointToPseudoAngle (bspcoord[check[0]], bspcoord[check[1]]);
 	angle2 = PointToPseudoAngle (bspcoord[check[2]], bspcoord[check[3]]);
 
-	if (vp->IsOrtho())
+	if (vp->bDoOrtho)
 	{
 	  if (angle2 != angle1) return true;
 	  switch (boxpos) // Check if the closer corner is poking into the view area
@@ -570,7 +570,7 @@ bool Clipper::CheckBoxOrthoPitch(const float *bspcoord)
 {
 	angle_t pitchmin, pitchmax;
 	auto &vp = viewpoint;
-	if (!vp->IsOrtho()) return true;
+	if (!vp->bDoOrtho) return true;
 
 	angle_t pitchtemp;
 	double padding = 1.0/viewpoint->ScreenProj/viewpoint->PitchCos;
diff --git a/src/rendering/hwrenderer/scene/hw_drawinfo.cpp b/src/rendering/hwrenderer/scene/hw_drawinfo.cpp
index a9f866a5c..6862b8d03 100644
--- a/src/rendering/hwrenderer/scene/hw_drawinfo.cpp
+++ b/src/rendering/hwrenderer/scene/hw_drawinfo.cpp
@@ -270,7 +270,7 @@ void HWDrawInfo::ClearBuffers()
 void HWDrawInfo::UpdateCurrentMapSection()
 {
 	int mapsection = Level->PointInRenderSubsector(Viewpoint.Pos)->mapsection;
-	if (Viewpoint.IsAllowedOoB() || Viewpoint.IsOrtho())
+	if (Viewpoint.bDoOob || Viewpoint.bDoOrtho)
 		mapsection = Level->PointInRenderSubsector(Viewpoint.OffPos)->mapsection;
 	CurrentMapSections.Set(mapsection);
 }
@@ -287,7 +287,7 @@ void HWDrawInfo::SetViewArea()
 	auto &vp = Viewpoint;
 	// The render_sector is better suited to represent the current position in GL
 	vp.sector = Level->PointInRenderSubsector(vp.Pos)->render_sector;
-	if (Viewpoint.IsAllowedOoB())
+	if (Viewpoint.bDoOob)
 		vp.sector = Level->PointInRenderSubsector(vp.camera->Pos())->render_sector;
 
 	// Get the heightsec state from the render sector, not the current one!
@@ -387,7 +387,7 @@ angle_t OoBFrustumAngle(FRenderViewpoint* Viewpoint)
 
 angle_t HWDrawInfo::FrustumAngle()
 {
-	if (Viewpoint.IsAllowedOoB())
+	if (Viewpoint.bDoOob)
 	{
 		return OoBFrustumAngle(&Viewpoint);
 	}
@@ -484,7 +484,7 @@ void HWDrawInfo::CreateScene(bool drawpsprites)
 	angle_t a1 = FrustumAngle(); // horizontally clip the back of the viewport
 	mClipper->SafeAddClipRangeRealAngles(vp.Angles.Yaw.BAMs() + a1, vp.Angles.Yaw.BAMs() - a1);
 	Viewpoint.FrustAngle = a1;
-	if (Viewpoint.IsAllowedOoB()) // No need for vertical clipper if viewpoint not allowed out of bounds
+	if (Viewpoint.bDoOob) // No need for vertical clipper if viewpoint not allowed out of bounds
 	{
 		double a2 = 20.0 + 0.5*Viewpoint.FieldOfView.Degrees(); // FrustumPitch for vertical clipping
 		if (a2 > 179.0) a2 = 179.0;
@@ -812,7 +812,7 @@ void HWDrawInfo::SetDitherTransFlags(AActor* actor)
 		double horiy = Viewpoint.Cos * actor->radius;
 		DVector3 actorpos = actor->Pos();
 		DVector3 vvec = actorpos - Viewpoint.Pos;
-		if (Viewpoint.IsOrtho())
+		if (Viewpoint.bDoOrtho)
 		{
 			vvec = 5.0 * Viewpoint.camera->ViewPos->Offset.Length() * Viewpoint.ViewVector3D; // Should be 4.0? (since zNear is behind screen by 3*dist in VREyeInfo::GetProjection())
 		}
@@ -1010,7 +1010,7 @@ void HWDrawInfo::DrawScene(int drawmode)
 	{
 		ssao_portals_available = gl_ssao_portals;
 		applySSAO = true;
-		if (r_dithertransparency && vp.IsAllowedOoB())
+		if (r_dithertransparency && vp.bDoOob)
 		{
 			vp.camera->tracer ? SetDitherTransFlags(vp.camera->tracer) : SetDitherTransFlags(players[consoleplayer].mo);
 		}
@@ -1068,7 +1068,7 @@ void HWDrawInfo::ProcessScene(bool toscreen)
 	portalState.BeginScene();
 
 	int mapsection = Level->PointInRenderSubsector(Viewpoint.Pos)->mapsection;
-	if (Viewpoint.IsAllowedOoB() || Viewpoint.IsOrtho())
+	if (Viewpoint.bDoOob || Viewpoint.bDoOrtho)
 		mapsection = Level->PointInRenderSubsector(Viewpoint.OffPos)->mapsection;
 	CurrentMapSections.Set(mapsection);
 	DrawScene(toscreen ? DM_MAINVIEW : DM_OFFSCREEN);
diff --git a/src/rendering/hwrenderer/scene/hw_flats.cpp b/src/rendering/hwrenderer/scene/hw_flats.cpp
index d53092c01..178c6872f 100644
--- a/src/rendering/hwrenderer/scene/hw_flats.cpp
+++ b/src/rendering/hwrenderer/scene/hw_flats.cpp
@@ -532,7 +532,7 @@ void HWFlat::ProcessSector(HWDrawInfo *di, sector_t * frontsector, int which)
 	//
 	//
 	//
-	if ((which & SSRF_RENDERFLOOR) && (vp.IsOrtho() ? vp.ViewVector3D.dot(frontsector->floorplane.Normal()) < 0.0 : frontsector->floorplane.ZatPoint(vp.Pos) <= vp.Pos.Z) && (!section || !(section->flags & FSection::DONTRENDERFLOOR)))
+	if ((which & SSRF_RENDERFLOOR) && (vp.bDoOrtho ? vp.ViewVector3D.dot(frontsector->floorplane.Normal()) < 0.0 : frontsector->floorplane.ZatPoint(vp.Pos) <= vp.Pos.Z) && (!section || !(section->flags & FSection::DONTRENDERFLOOR)))
 	{
 		// process the original floor first.
 
@@ -590,7 +590,7 @@ void HWFlat::ProcessSector(HWDrawInfo *di, sector_t * frontsector, int which)
 	//
 	// 
 	//
-	if ((which & SSRF_RENDERCEILING) && (vp.IsOrtho() ? vp.ViewVector3D.dot(frontsector->ceilingplane.Normal()) < 0.0 : frontsector->ceilingplane.ZatPoint(vp.Pos) >= vp.Pos.Z) && (!section || !(section->flags & FSection::DONTRENDERCEILING)))
+	if ((which & SSRF_RENDERCEILING) && (vp.bDoOrtho ? vp.ViewVector3D.dot(frontsector->ceilingplane.Normal()) < 0.0 : frontsector->ceilingplane.ZatPoint(vp.Pos) >= vp.Pos.Z) && (!section || !(section->flags & FSection::DONTRENDERCEILING)))
 	{
 		// process the original ceiling first.
 
@@ -675,7 +675,7 @@ void HWFlat::ProcessSector(HWDrawInfo *di, sector_t * frontsector, int which)
 					double ff_top = rover->top.plane->ZatPoint(sector->centerspot);
 					if (ff_top < lastceilingheight)
 					{
-						if ((vp.IsOrtho() ? vp.ViewVector3D.dot(rover->top.plane->Normal()) > 0.0 : vp.Pos.Z <= rover->top.plane->ZatPoint(vp.Pos)))
+						if ((vp.bDoOrtho ? vp.ViewVector3D.dot(rover->top.plane->Normal()) > 0.0 : vp.Pos.Z <= rover->top.plane->ZatPoint(vp.Pos)))
 						{
 							SetFrom3DFloor(rover, true, !!(rover->flags&FF_FOG));
 							Colormap.FadeColor = frontsector->Colormap.FadeColor;
@@ -689,7 +689,7 @@ void HWFlat::ProcessSector(HWDrawInfo *di, sector_t * frontsector, int which)
 					double ff_bottom = rover->bottom.plane->ZatPoint(sector->centerspot);
 					if (ff_bottom < lastceilingheight)
 					{
-						if ((vp.IsOrtho() ? vp.ViewVector3D.dot(rover->bottom.plane->Normal()) > 0.0 : vp.Pos.Z <= rover->bottom.plane->ZatPoint(vp.Pos)))
+						if ((vp.bDoOrtho ? vp.ViewVector3D.dot(rover->bottom.plane->Normal()) > 0.0 : vp.Pos.Z <= rover->bottom.plane->ZatPoint(vp.Pos)))
 						{
 							SetFrom3DFloor(rover, false, !(rover->flags&FF_FOG));
 							Colormap.FadeColor = frontsector->Colormap.FadeColor;
@@ -715,7 +715,7 @@ void HWFlat::ProcessSector(HWDrawInfo *di, sector_t * frontsector, int which)
 					double ff_bottom = rover->bottom.plane->ZatPoint(sector->centerspot);
 					if (ff_bottom > lastfloorheight || (rover->flags&FF_FIX))
 					{
-						if ((vp.IsOrtho() ? vp.ViewVector3D.dot(rover->bottom.plane->Normal()) > 0.0 : vp.Pos.Z >= rover->bottom.plane->ZatPoint(vp.Pos)))
+						if ((vp.bDoOrtho ? vp.ViewVector3D.dot(rover->bottom.plane->Normal()) > 0.0 : vp.Pos.Z >= rover->bottom.plane->ZatPoint(vp.Pos)))
 						{
 							SetFrom3DFloor(rover, false, !(rover->flags&FF_FOG));
 							Colormap.FadeColor = frontsector->Colormap.FadeColor;
@@ -736,7 +736,7 @@ void HWFlat::ProcessSector(HWDrawInfo *di, sector_t * frontsector, int which)
 					double ff_top = rover->top.plane->ZatPoint(sector->centerspot);
 					if (ff_top > lastfloorheight)
 					{
-						if ((vp.IsOrtho() ? vp.ViewVector3D.dot(rover->top.plane->Normal()) > 0.0 : vp.Pos.Z >= rover->top.plane->ZatPoint(vp.Pos)))
+						if ((vp.bDoOrtho ? vp.ViewVector3D.dot(rover->top.plane->Normal()) > 0.0 : vp.Pos.Z >= rover->top.plane->ZatPoint(vp.Pos)))
 						{
 							SetFrom3DFloor(rover, true, !!(rover->flags&FF_FOG));
 							Colormap.FadeColor = frontsector->Colormap.FadeColor;
diff --git a/src/rendering/hwrenderer/scene/hw_portal.cpp b/src/rendering/hwrenderer/scene/hw_portal.cpp
index 0963405db..c80d3c308 100644
--- a/src/rendering/hwrenderer/scene/hw_portal.cpp
+++ b/src/rendering/hwrenderer/scene/hw_portal.cpp
@@ -125,7 +125,7 @@ bool FPortalSceneState::RenderFirstSkyPortal(int recursion, HWDrawInfo *outer_di
 {
 	HWPortal * best = nullptr;
 	unsigned bestindex = 0;
-	bool usestencil = outer_di->Viewpoint.IsAllowedOoB();
+	bool usestencil = outer_di->Viewpoint.bDoOob;
 
 	// Find the one with the highest amount of lines.
 	// Normally this is also the one that saves the largest amount
@@ -507,7 +507,7 @@ bool HWMirrorPortal::Setup(HWDrawInfo *di, FRenderState &rstate, Clipper *clippe
 	}
 
 	auto &vp = di->Viewpoint;
-	state->vpIsAllowedOoB = vp.IsAllowedOoB();
+	state->vpIsAllowedOoB = vp.bDoOob;
 	di->UpdateCurrentMapSection();
 
 	di->mClipPortal = this;
@@ -576,7 +576,7 @@ bool HWMirrorPortal::Setup(HWDrawInfo *di, FRenderState &rstate, Clipper *clippe
 	angle_t af = di->FrustumAngle();
 	if (af < ANGLE_180) clipper->SafeAddClipRangeRealAngles(vp.Angles.Yaw.BAMs() + af, vp.Angles.Yaw.BAMs() - af);
 
-	if(!di->Viewpoint.IsAllowedOoB())
+	if(!di->Viewpoint.bDoOob)
 		clipper->SafeAddClipRange(linedef->v1, linedef->v2);
 	return true;
 }
@@ -612,7 +612,7 @@ bool HWLineToLinePortal::Setup(HWDrawInfo *di, FRenderState &rstate, Clipper *cl
 		return false;
 	}
 	auto &vp = di->Viewpoint;
-	state->vpIsAllowedOoB = vp.IsAllowedOoB();
+	state->vpIsAllowedOoB = vp.bDoOob;
 	di->mClipPortal = this;
 
 	line_t *origin = glport->lines[0]->mOrigin;
@@ -692,7 +692,7 @@ bool HWSkyboxPortal::Setup(HWDrawInfo *di, FRenderState &rstate, Clipper *clippe
 		return false;
 	}
 	auto &vp = di->Viewpoint;
-	state->vpIsAllowedOoB = vp.IsAllowedOoB();
+	state->vpIsAllowedOoB = vp.bDoOob;
 
 	state->skyboxrecursion++;
 	state->PlaneMirrorMode = 0;
@@ -804,7 +804,7 @@ bool HWSectorStackPortal::Setup(HWDrawInfo *di, FRenderState &rstate, Clipper *c
 
 	FSectorPortalGroup *portal = origin;
 	auto &vp = di->Viewpoint;
-	state->vpIsAllowedOoB = vp.IsAllowedOoB();
+	state->vpIsAllowedOoB = vp.bDoOob;
 
 	vp.Pos += origin->mDisplacement;
 	vp.ActorPos += origin->mDisplacement;
@@ -813,7 +813,7 @@ bool HWSectorStackPortal::Setup(HWDrawInfo *di, FRenderState &rstate, Clipper *c
 
 	// avoid recursions!
 	if (origin->plane != -1) screen->instack[origin->plane]++;
-	if (vp.IsAllowedOoB() && lines.Size() > 0)
+	if (vp.bDoOob && lines.Size() > 0)
 	{
 
 		flat.plane.GetFromSector(lines[0].sub->sector, origin->plane);
@@ -827,7 +827,7 @@ bool HWSectorStackPortal::Setup(HWDrawInfo *di, FRenderState &rstate, Clipper *c
 	// If the viewpoint is not within the portal, we need to invalidate the entire clip area.
 	// The portal will re-validate the necessary parts when its subsectors get traversed.
 	subsector_t *sub = di->Level->PointInRenderSubsector(vp.Pos);
-	if (vp.IsAllowedOoB()) sub = di->Level->PointInRenderSubsector(vp.OffPos);
+	if (vp.bDoOob) sub = di->Level->PointInRenderSubsector(vp.OffPos);
 	if (!(di->ss_renderflags[sub->Index()] & SSRF_SEEN))
 	{
 		clipper->SafeAddClipRange(0, ANGLE_MAX);
@@ -895,7 +895,7 @@ bool HWPlaneMirrorPortal::Setup(HWDrawInfo *di, FRenderState &rstate, Clipper *c
 	std::swap(screen->instack[sector_t::floor], screen->instack[sector_t::ceiling]);
 
 	auto &vp = di->Viewpoint;
-	state->vpIsAllowedOoB = vp.IsAllowedOoB();
+	state->vpIsAllowedOoB = vp.bDoOob;
 	old_pm = state->PlaneMirrorMode;
 
 	// the player is always visible in a mirror.
@@ -951,6 +951,8 @@ void HWPlaneMirrorPortal::Shutdown(HWDrawInfo *di, FRenderState &rstate)
 
 const char *HWPlaneMirrorPortal::GetName() { return origin->fC() < 0? "Planemirror ceiling" : "Planemirror floor"; }
 
+int HWPlaneMirrorPortal::GetMirrorSide() const { return origin->fC() < 0 ? -1 : 1; };
+
 
 //-----------------------------------------------------------------------------
 //-----------------------------------------------------------------------------
diff --git a/src/rendering/hwrenderer/scene/hw_portal.h b/src/rendering/hwrenderer/scene/hw_portal.h
index 64952b88b..139225a58 100644
--- a/src/rendering/hwrenderer/scene/hw_portal.h
+++ b/src/rendering/hwrenderer/scene/hw_portal.h
@@ -70,6 +70,7 @@ public:
     {
     }
     virtual ~HWPortal() {}
+	virtual int GetMirrorSide() const { return 0; };
     virtual int ClipSeg(seg_t *seg, const DVector3 &viewpos) { return PClip_Inside; }
     virtual int ClipSubsector(subsector_t *sub) { return PClip_Inside; }
     virtual int ClipPoint(const DVector2 &pos) { return PClip_Inside; }
@@ -148,7 +149,7 @@ public:
 	virtual bool NeedDepthBuffer() { return true; }
 	virtual void DrawContents(HWDrawInfo *di, FRenderState &state)
 	{
-		if (Setup(di, state, (di->Viewpoint.IsAllowedOoB() ? di->rClipper : di->mClipper)))
+		if (Setup(di, state, (di->Viewpoint.bDoOob ? di->rClipper : di->mClipper)))
 		{
 			di->DrawScene(DM_PORTAL);
 			Shutdown(di, state);
@@ -304,6 +305,8 @@ protected:
 
 public:
 
+	int GetMirrorSide() const override;
+
 	HWPlaneMirrorPortal(FPortalSceneState *state, secplane_t * pt) : HWScenePortalBase(state)
 	{
 		origin = pt;
diff --git a/src/rendering/hwrenderer/scene/hw_sky.cpp b/src/rendering/hwrenderer/scene/hw_sky.cpp
index e8645e8dc..ff9ef4e72 100644
--- a/src/rendering/hwrenderer/scene/hw_sky.cpp
+++ b/src/rendering/hwrenderer/scene/hw_sky.cpp
@@ -157,10 +157,10 @@ void HWWall::SkyPlane(HWWallDispatcher *di, sector_t *sector, int plane, bool al
 		case PORTS_PORTAL:
 		case PORTS_LINKEDPORTAL:
 		{
-			if (di->di && di->di->Viewpoint.IsAllowedOoB())
+			if (di->di && di->di->Viewpoint.bDoOob)
 			{
 				secplane_t myplane = plane ? sector->ceilingplane : sector->floorplane;
-				if (di->di->Viewpoint.IsOrtho() && di->di->Viewpoint.ViewVector3D.dot(myplane.Normal()) > 0.0) return;
+				if (di->di->Viewpoint.bDoOrtho && di->di->Viewpoint.ViewVector3D.dot(myplane.Normal()) > 0.0) return;
 				else if (plane==1 && di->di->Viewpoint.Pos.Z >= myplane.ZatPoint(di->di->Viewpoint.Pos)) return;
 				else if (plane==0 && di->di->Viewpoint.Pos.Z <= myplane.ZatPoint(di->di->Viewpoint.Pos)) return;
 			}
@@ -323,7 +323,7 @@ void HWWall::SkyTop(HWWallDispatcher *di, seg_t * seg,sector_t * fs,sector_t * b
 			// if (backreflect > 0 && bs->ceilingplane.fD() == fs->ceilingplane.fD() && !bs->isClosed())
 			// {
 			// 	Don't add intra-portal line to the portal.
-			// 	if (!(di->di && di->di->Viewpoint.IsAllowedOoB()))
+			// 	if (!(di->di && di->di->Viewpoint.bDoOob))
 			// 	{
 			// 		return;
 			// 	}
@@ -406,7 +406,7 @@ void HWWall::SkyBottom(HWWallDispatcher *di, seg_t * seg,sector_t * fs,sector_t
 			// if (backreflect > 0 && bs->floorplane.fD() == fs->floorplane.fD() && !bs->isClosed())
 			// {
 			// 	// Don't add intra-portal line to the portal.
-			// 	if (!(di->di && di->di->Viewpoint.IsAllowedOoB()))
+			// 	if (!(di->di && di->di->Viewpoint.bDoOob))
 			// 	{
 			// 		return;
 			// 	}
diff --git a/src/rendering/hwrenderer/scene/hw_sprites.cpp b/src/rendering/hwrenderer/scene/hw_sprites.cpp
index d29766350..f5cda4466 100644
--- a/src/rendering/hwrenderer/scene/hw_sprites.cpp
+++ b/src/rendering/hwrenderer/scene/hw_sprites.cpp
@@ -547,7 +547,7 @@ bool HWSprite::CalculateVertices(HWDrawInfo* di, FVector3* v, DVector3* vp)
 				mat.Translate(-center.X, -center.Z, -center.Y);
 			}
 
-			if (actor && (actor->renderflags2 & RF2_ISOMETRICSPRITES) && di->Viewpoint.IsOrtho())
+			if (actor && (actor->renderflags2 & RF2_ISOMETRICSPRITES) && di->Viewpoint.bDoOrtho)
 			{
 				float angleRad = (FAngle::fromDeg(270.) - HWAngles.Yaw).Radians();
 				mat.Translate(center.X, center.Z, center.Y);
@@ -952,7 +952,7 @@ void HWSprite::Process(HWDrawInfo *di, AActor* thing, sector_t * sector, area_t
 		bool mirror = false;
 		bool backfaced = false;
 		DAngle ang = (thingpos - vp.Pos).Angle();
-		if (di->Viewpoint.IsOrtho()) ang = vp.Angles.Yaw;
+		if (di->Viewpoint.bDoOrtho) ang = vp.Angles.Yaw;
 		else if (actor && thing->renderflags2 & RF2_ANGLEDROLL)
 		{
 			Matrix3x4 rolltilt;
diff --git a/src/rendering/hwrenderer/scene/hw_walls.cpp b/src/rendering/hwrenderer/scene/hw_walls.cpp
index 557004f53..7ff0fa7d8 100644
--- a/src/rendering/hwrenderer/scene/hw_walls.cpp
+++ b/src/rendering/hwrenderer/scene/hw_walls.cpp
@@ -706,7 +706,7 @@ void HWWall::PutPortal(HWWallDispatcher *di, int ptype, int plane)
 			break;
 
 		case PORTALTYPE_PLANEMIRROR:
-			if (ddi->Viewpoint.IsOrtho() ? (ddi->Viewpoint.ViewVector3D.dot(planemirror->Normal()) < 0)
+			if (ddi->Viewpoint.bDoOrtho ? (ddi->Viewpoint.ViewVector3D.dot(planemirror->Normal()) < 0)
 				: (portalState.PlaneMirrorMode * planemirror->fC() <= 0))
 			{
 				planemirror = portalState.UniquePlaneMirrors.Get(planemirror);
diff --git a/src/rendering/r_utility.cpp b/src/rendering/r_utility.cpp
index ab0a8c6e6..d97de3e3d 100644
--- a/src/rendering/r_utility.cpp
+++ b/src/rendering/r_utility.cpp
@@ -550,7 +550,7 @@ void R_InterpolateView(FRenderViewpoint& viewPoint, const player_t* const player
 			const int prevPortalGroup = viewLvl->PointInRenderSubsector(iView->Old.Pos)->sector->PortalGroup;
 			const int curPortalGroup = viewLvl->PointInRenderSubsector(iView->New.Pos)->sector->PortalGroup;
 
-			if (viewPoint.IsAllowedOoB() && prevPortalGroup != curPortalGroup) viewPoint.Pos = iView->New.Pos;
+			if (viewPoint.bDoOob && prevPortalGroup != curPortalGroup) viewPoint.Pos = iView->New.Pos;
 			else
 			{
 				const DVector2 portalOffset = viewLvl->Displacements.getOffset(prevPortalGroup, curPortalGroup);
@@ -567,7 +567,7 @@ void R_InterpolateView(FRenderViewpoint& viewPoint, const player_t* const player
 
 	// Due to interpolation this is not necessarily the same as the sector the camera is in.
 	viewPoint.sector = viewLvl->PointInRenderSubsector(viewPoint.Pos)->sector;
-	if (!viewPoint.IsAllowedOoB() || !V_IsHardwareRenderer())
+	if (!viewPoint.bDoOob || !V_IsHardwareRenderer())
 	{
 		bool moved = false;
 		while (!viewPoint.sector->PortalBlocksMovement(sector_t::ceiling))
@@ -712,7 +712,7 @@ void FRenderViewpoint::SetViewAngle(const FViewWindow& viewWindow)
 	ViewVector3D.Y = v.Y * PitchCos;
 	ViewVector3D.Z = -PitchSin;
 
-	if (IsOrtho() || IsAllowedOoB()) // These auto-ensure that camera and camera->ViewPos exist
+	if (bDoOrtho || bDoOob) // These auto-ensure that camera and camera->ViewPos exist
 	{
 		if (camera->tracer != NULL)
 		{
@@ -724,7 +724,7 @@ void FRenderViewpoint::SetViewAngle(const FViewWindow& viewWindow)
 		}
 	}
 
-	if (IsOrtho() && (camera->ViewPos->Offset.XY().Length() > 0.0))
+	if (bDoOrtho && (camera->ViewPos->Offset.XY().Length() > 0.0))
 	{
 		ScreenProj = 1.34396 / camera->ViewPos->Offset.Length() / tan (FieldOfView.Radians()*0.5); // [DVR] Estimated. +/-1 should be top/bottom of screen.
 		ScreenProjX = ScreenProj * 0.5 / viewWindow.WidescreenRatio;
@@ -953,6 +953,9 @@ void R_SetupFrame(FRenderViewpoint& viewPoint, const FViewWindow& viewWindow, AA
 	if (viewPoint.camera == nullptr)
 		I_Error("You lost your body. Bad dehacked work is likely to blame.");
 
+	viewPoint.bDoOob = viewPoint.IsAllowedOoB();
+	viewPoint.bDoOrtho = viewPoint.IsOrtho();
+
 	InterpolationViewer* const iView = FindPastViewer(viewPoint.camera);
 	// Always reset these back to zero.
 	iView->ViewOffset.Zero();
@@ -1101,14 +1104,14 @@ void R_SetupFrame(FRenderViewpoint& viewPoint, const FViewWindow& viewWindow, AA
 
 	// Keep the view within the sector's floor and ceiling
 	// But allow VPSF_ALLOWOUTOFBOUNDS camera viewpoints to go out of bounds when using hardware renderer
-	if (viewPoint.sector->PortalBlocksMovement(sector_t::ceiling) && (!viewPoint.IsAllowedOoB() || !V_IsHardwareRenderer()))
+	if (viewPoint.sector->PortalBlocksMovement(sector_t::ceiling) && (!viewPoint.bDoOob || !V_IsHardwareRenderer()))
 	{
 		const double z = viewPoint.sector->ceilingplane.ZatPoint(viewPoint.Pos) - 4.0;
 		if (viewPoint.Pos.Z > z)
 			viewPoint.Pos.Z = z;
 	}
 
-	if (viewPoint.sector->PortalBlocksMovement(sector_t::floor) && (!viewPoint.IsAllowedOoB() || !V_IsHardwareRenderer()))
+	if (viewPoint.sector->PortalBlocksMovement(sector_t::floor) && (!viewPoint.bDoOob || !V_IsHardwareRenderer()))
 	{
 		const double z = viewPoint.sector->floorplane.ZatPoint(viewPoint.Pos) + 4.0;
 		if (viewPoint.Pos.Z < z)
diff --git a/src/rendering/r_utility.h b/src/rendering/r_utility.h
index 0c2f47833..dab98dfea 100644
--- a/src/rendering/r_utility.h
+++ b/src/rendering/r_utility.h
@@ -53,6 +53,8 @@ struct FRenderViewpoint
 	int				extralight;		// extralight to be added to this viewpoint
 	bool			showviewer;		// show the camera actor?
 	bool			bForceNoViewer; // Never show the camera Actor.
+	bool			bDoOob;
+	bool			bDoOrtho;
 	void SetViewAngle(const FViewWindow& viewWindow);
 	bool IsAllowedOoB();				// Checks if camera actor exists, has viewpos, and viewpos has VPSF_ALLOWOUTOFBOUNDS flag set
 	bool IsOrtho();					// Checks if camera actor exists, has viewpos, and viewpos has VPSF_ORTHOGRAPHIC flag set