diff --git a/src/polyrenderer/scene/poly_cull.cpp b/src/polyrenderer/scene/poly_cull.cpp
index 647dc54a2..623b6e9df 100644
--- a/src/polyrenderer/scene/poly_cull.cpp
+++ b/src/polyrenderer/scene/poly_cull.cpp
@@ -70,26 +70,6 @@ void PolyCull::CullNode(void *node)
 
 void PolyCull::CullSubsector(subsector_t *sub)
 {
-	// Mark poly objects first
-	if (sub->polys)
-	{
-		if (sub->BSP == nullptr || sub->BSP->bDirty)
-		{
-			sub->BuildPolyBSP();
-		}
-		
-		if (sub->BSP->Nodes.Size() == 0)
-		{
-			CullSubsector(&sub->BSP->Subsectors[0]);
-		}
-		else
-		{
-			CullNode(&sub->BSP->Nodes.Last());
-		}
-		
-		return; // Hmm, seems a bit strange the subsector is then ignored. But that's what the sw renderer seems to be doing..
-	}
-	
 	// Update sky heights for the scene
 	if (!FirstSkyHeight)
 	{
diff --git a/src/polyrenderer/scene/poly_scene.cpp b/src/polyrenderer/scene/poly_scene.cpp
index a655ca845..21ae23fc8 100644
--- a/src/polyrenderer/scene/poly_scene.cpp
+++ b/src/polyrenderer/scene/poly_scene.cpp
@@ -111,25 +111,48 @@ void RenderPolyScene::RenderSubsector(subsector_t *sub)
 
 	uint32_t subsectorDepth = NextSubsectorDepth++;
 
+	bool mainBSP = sub->polys == nullptr;
+
+	if (sub->polys)
+	{
+		if (sub->BSP == nullptr || sub->BSP->bDirty)
+		{
+			sub->BuildPolyBSP();
+
+			// This is done by the GL renderer, but not the sw renderer. No idea what the purpose is..
+			for (unsigned i = 0; i < sub->BSP->Segs.Size(); i++)
+			{
+				sub->BSP->Segs[i].Subsector = sub;
+				sub->BSP->Segs[i].PartnerSeg = nullptr;
+			}
+		}
+
+		if (sub->BSP->Nodes.Size() == 0)
+		{
+			RenderPolySubsector(&sub->BSP->Subsectors[0], subsectorDepth, frontsector);
+		}
+		else
+		{
+			RenderPolyNode(&sub->BSP->Nodes.Last(), subsectorDepth, frontsector);
+		}
+	}
+	else
+	{
+		for (uint32_t i = 0; i < sub->numlines; i++)
+		{
+			seg_t *line = &sub->firstline[i];
+			RenderLine(sub, line, frontsector, subsectorDepth);
+		}
+	}
+
 	if (sub->sector->CenterFloor() != sub->sector->CenterCeiling())
 	{
 		RenderPolyPlane::RenderPlanes(WorldToClip, PortalPlane, Cull, sub, subsectorDepth, StencilValue, Cull.MaxCeilingHeight, Cull.MinFloorHeight, SectorPortals);
 	}
 
-	for (uint32_t i = 0; i < sub->numlines; i++)
-	{
-		seg_t *line = &sub->firstline[i];
-		if (line->sidedef == nullptr || !(line->sidedef->Flags & WALLF_POLYOBJ))
-		{
-			RenderLine(sub, line, frontsector, subsectorDepth);
-		}
-	}
-
-	RenderMemory &memory = PolyRenderer::Instance()->FrameMemory;
-
-	bool mainBSP = ((unsigned int)(sub->Index()) < level.subsectors.Size());
 	if (mainBSP)
 	{
+		RenderMemory &memory = PolyRenderer::Instance()->FrameMemory;
 		int subsectorIndex = sub->Index();
 		for (int i = ParticlesInSubsec[subsectorIndex]; i != NO_PARTICLE; i = Particles[i].snext)
 		{
@@ -142,6 +165,73 @@ void RenderPolyScene::RenderSubsector(subsector_t *sub)
 	SubsectorDepths[sub] = subsectorDepth;
 }
 
+void RenderPolyScene::RenderPolyNode(void *node, uint32_t subsectorDepth, sector_t *frontsector)
+{
+	while (!((size_t)node & 1))  // Keep going until found a subsector
+	{
+		node_t *bsp = (node_t *)node;
+
+		// Decide which side the view point is on.
+		int side = PointOnSide(PolyRenderer::Instance()->Viewpoint.Pos, bsp);
+
+		// Recursively divide front space (toward the viewer).
+		RenderPolyNode(bsp->children[side], subsectorDepth, frontsector);
+
+		// Possibly divide back space (away from the viewer).
+		side ^= 1;
+
+		// Don't bother culling on poly objects
+		//if (!CheckBBox(bsp->bbox[side]))
+		//	return;
+
+		node = bsp->children[side];
+	}
+
+	subsector_t *sub = (subsector_t *)((uint8_t *)node - 1);
+	RenderPolySubsector(sub, subsectorDepth, frontsector);
+}
+
+void RenderPolyScene::RenderPolySubsector(subsector_t *sub, uint32_t subsectorDepth, sector_t *frontsector)
+{
+	const auto &viewpoint = PolyRenderer::Instance()->Viewpoint;
+
+	for (uint32_t i = 0; i < sub->numlines; i++)
+	{
+		seg_t *line = &sub->firstline[i];
+		if (line->linedef)
+		{
+			// Reject lines not facing viewer
+			DVector2 pt1 = line->v1->fPos() - viewpoint.Pos;
+			DVector2 pt2 = line->v2->fPos() - viewpoint.Pos;
+			if (pt1.Y * (pt1.X - pt2.X) + pt1.X * (pt2.Y - pt1.Y) >= 0)
+				continue;
+
+			// Cull wall if not visible
+			angle_t angle1, angle2;
+			if (!Cull.GetAnglesForLine(line->v1->fX(), line->v1->fY(), line->v2->fX(), line->v2->fY(), angle1, angle2))
+				continue;
+
+			// Tell automap we saw this
+			if (!PolyRenderer::Instance()->DontMapLines && line->linedef)
+			{
+				line->linedef->flags |= ML_MAPPED;
+				sub->flags |= SSECF_DRAWN;
+			}
+
+			// Render wall, and update culling info if its an occlusion blocker
+			if (RenderPolyWall::RenderLine(WorldToClip, PortalPlane, Cull, line, frontsector, subsectorDepth, StencilValue, TranslucentObjects, LinePortals))
+			{
+				Cull.MarkSegmentCulled(angle1, angle2);
+			}
+		}
+	}
+}
+
+int RenderPolyScene::PointOnSide(const DVector2 &pos, const node_t *node)
+{
+	return DMulScale32(FLOAT2FIXED(pos.Y) - node->y, node->dx, node->x - FLOAT2FIXED(pos.X), node->dy) > 0;
+}
+
 void RenderPolyScene::RenderSprite(AActor *thing, double sortDistance, const DVector2 &left, const DVector2 &right)
 {
 	if (level.nodes.Size() == 0)
diff --git a/src/polyrenderer/scene/poly_scene.h b/src/polyrenderer/scene/poly_scene.h
index 707ee87a3..fc89de7cd 100644
--- a/src/polyrenderer/scene/poly_scene.h
+++ b/src/polyrenderer/scene/poly_scene.h
@@ -89,6 +89,10 @@ private:
 	void RenderSprite(AActor *thing, double sortDistance, const DVector2 &left, const DVector2 &right);
 	void RenderSprite(AActor *thing, double sortDistance, DVector2 left, DVector2 right, double t1, double t2, void *node);
 
+	void RenderPolySubsector(subsector_t *sub, uint32_t subsectorDepth, sector_t *frontsector);
+	void RenderPolyNode(void *node, uint32_t subsectorDepth, sector_t *frontsector);
+	static int PointOnSide(const DVector2 &pos, const node_t *node);
+
 	TriMatrix WorldToClip;
 	PolyClipPlane PortalPlane;
 	uint32_t StencilValue = 0;