diff --git a/src/polyrenderer/scene/poly_plane.cpp b/src/polyrenderer/scene/poly_plane.cpp
index 926092f5c..f267bde58 100644
--- a/src/polyrenderer/scene/poly_plane.cpp
+++ b/src/polyrenderer/scene/poly_plane.cpp
@@ -430,17 +430,15 @@ void Render3DFloorPlane::RenderPlanes(PolyRenderThread *thread, subsector_t *sub
 	for (int i = 0; i < (int)ffloors.Size(); i++)
 	{
 		F3DFloor *fakeFloor = ffloors[i];
+		F3DFloor *prevFloor = i > 0 ? ffloors[i - 1] : nullptr;
 		if (!(fakeFloor->flags & FF_EXISTS)) continue;
 		if (!fakeFloor->model) continue;
-		//if (!(fakeFloor->flags & FF_NOSHADE) || (fakeFloor->flags & (FF_RENDERPLANES | FF_RENDERSIDES)))
-		//	R_3D_AddHeight(fakeFloor->top.plane, frontsector);
 		if (!(fakeFloor->flags & FF_RENDERPLANES)) continue;
 		if (fakeFloor->alpha == 0) continue;
-		if (fakeFloor->flags & FF_THISINSIDE && fakeFloor->flags & FF_INVERTSECTOR) continue;
-		//fakeFloor->alpha
+		if (prevFloor && (prevFloor->flags & fakeFloor->flags & FF_SWIMMABLE)) continue;
 
 		double fakeHeight = fakeFloor->top.plane->ZatPoint(frontsector->centerspot);
-		if (fakeFloor->bottom.plane->isSlope() || (fakeHeight < viewpoint.Pos.Z && fakeHeight > frontsector->floorplane.ZatPoint(frontsector->centerspot)))
+		if (fakeFloor->top.plane->isSlope() || (fakeHeight < viewpoint.Pos.Z && fakeHeight > frontsector->floorplane.ZatPoint(frontsector->centerspot)))
 		{
 			Render3DFloorPlane plane;
 			plane.sub = sub;
@@ -470,14 +468,12 @@ void Render3DFloorPlane::RenderPlanes(PolyRenderThread *thread, subsector_t *sub
 	for (int i = 0; i < (int)ffloors.Size(); i++)
 	{
 		F3DFloor *fakeFloor = ffloors[i];
+		F3DFloor *prevFloor = i > 0 ? ffloors[i - 1] : nullptr;
 		if (!(fakeFloor->flags & FF_EXISTS)) continue;
 		if (!fakeFloor->model) continue;
-		//if (!(fakeFloor->flags & FF_NOSHADE) || (fakeFloor->flags & (FF_RENDERPLANES | FF_RENDERSIDES)))
-		//	R_3D_AddHeight(fakeFloor->bottom.plane, frontsector);
 		if (!(fakeFloor->flags & FF_RENDERPLANES)) continue;
 		if (fakeFloor->alpha == 0) continue;
-		if (!(fakeFloor->flags & FF_THISINSIDE) && (fakeFloor->flags & (FF_SWIMMABLE | FF_INVERTSECTOR)) == (FF_SWIMMABLE | FF_INVERTSECTOR)) continue;
-		//fakeFloor->alpha
+		if (prevFloor && (prevFloor->flags & fakeFloor->flags & FF_SWIMMABLE)) continue;
 
 		double fakeHeight = fakeFloor->bottom.plane->ZatPoint(frontsector->centerspot);
 		if (fakeFloor->bottom.plane->isSlope() || (fakeHeight > viewpoint.Pos.Z && fakeHeight < frontsector->ceilingplane.ZatPoint(frontsector->centerspot)))
@@ -520,7 +516,7 @@ void Render3DFloorPlane::Render(PolyRenderThread *thread)
 	bool foggy = false;
 	if (cameraLight->FixedLightLevel() < 0 && sub->sector->e->XFloor.lightlist.Size())
 	{
-		lightlist_t *light = P_GetPlaneLight(sub->sector, &sub->sector->ceilingplane, false);
+		lightlist_t *light = P_GetPlaneLight(sub->sector, ceiling ? fakeFloor->bottom.plane : fakeFloor->top.plane, ceiling);
 		//basecolormap = light->extra_colormap;
 		lightlevel = *light->p_lightlevel;
 	}
@@ -553,15 +549,17 @@ void Render3DFloorPlane::Render(PolyRenderThread *thread)
 	if (!Masked)
 	{
 		args.SetStyle(TriBlendMode::Opaque);
+		args.SetStencilTestValue(stencilValue);
+		args.SetWriteStencil(true, stencilValue + 1);
 	}
 	else
 	{
 		args.SetStyle(Additive ? TriBlendMode::Add : TriBlendMode::Normal, MIN(Alpha, 1.0));
+		args.SetStencilTestValue(stencilValue + 1);
+		args.SetWriteStencil(false);
 		args.SetDepthTest(true);
 		args.SetWriteDepth(true);
 	}
-	args.SetStencilTestValue(stencilValue);
-	args.SetWriteStencil(true, stencilValue + 1);
 	args.SetTexture(tex->GetSoftwareTexture(), DefaultRenderStyle());
 	PolyTriangleDrawer::DrawArray(thread->DrawQueue, args, vertices, sub->numlines, PolyDrawMode::TriangleFan);
 }
diff --git a/src/polyrenderer/scene/poly_wall.cpp b/src/polyrenderer/scene/poly_wall.cpp
index 70472eef7..616de754e 100644
--- a/src/polyrenderer/scene/poly_wall.cpp
+++ b/src/polyrenderer/scene/poly_wall.cpp
@@ -196,7 +196,6 @@ void RenderPolyWall::Render3DFloorLine(PolyRenderThread *thread, seg_t *line, se
 {
 	if (!(fakeFloor->flags & FF_EXISTS)) return;
 	if (!(fakeFloor->flags & FF_RENDERPLANES)) return;
-	if (fakeFloor->flags & FF_SWIMMABLE) return;
 	if (!fakeFloor->model) return;
 	if (fakeFloor->alpha == 0) return;
 
@@ -210,12 +209,29 @@ void RenderPolyWall::Render3DFloorLine(PolyRenderThread *thread, seg_t *line, se
 	if (frontceilz1 <= frontfloorz1 || frontceilz2 <= frontfloorz2)
 		return;
 
+	if (fakeFloor->flags & FF_SWIMMABLE) // Only draw swimmable boundary if not swimmable on both sides
+	{
+		DVector2 c = (line->v1->fPos() + line->v2->fPos()) * 0.5;
+		double cz = (frontceilz1 + frontceilz2 + frontfloorz1 + frontfloorz2) * 0.25;
+		for (unsigned i = 0; i < frontsector->e->XFloor.ffloors.Size(); i++)
+		{
+			F3DFloor *frontFloor = frontsector->e->XFloor.ffloors[i];
+			if (!(frontFloor->flags & FF_EXISTS)) continue;
+			if (!(frontFloor->flags & FF_RENDERPLANES)) continue;
+			if (!frontFloor->model) continue;
+			if (frontFloor->alpha == 0) continue;
+			if (frontFloor->top.plane->ZatPoint(c) >= cz && frontFloor->bottom.plane->ZatPoint(c) <= cz && (frontFloor->flags & FF_SWIMMABLE))
+			{
+				return;
+			}
+		}
+	}
+
 	RenderPolyWall wall;
 	wall.LineSeg = line;
 	wall.LineSegLine = line->linedef;
 	wall.Line = fakeFloor->master;
 	wall.Side = fakeFloor->master->sidedef[0];
-	wall.SectorLightLevel = frontsector->lightlevel;
 	wall.Additive = !!(fakeFloor->flags & FF_ADDITIVETRANS);
 	if (!wall.Additive && fakeFloor->alpha == 255)
 	{
@@ -241,6 +257,18 @@ void RenderPolyWall::Render3DFloorLine(PolyRenderThread *thread, seg_t *line, se
 	else
 		wall.Texture = GetTexture(wall.Line, wall.Side, side_t::mid);
 
+	if (frontsector->e->XFloor.lightlist.Size())
+	{
+		lightlist_t *light = P_GetPlaneLight(frontsector, fakeFloor->top.plane, true);
+		wall.Colormap = GetColorTable(light->extra_colormap, wall.Side->GetSpecialColor(wall.Wallpart, side_t::walltop, frontsector));
+		wall.SectorLightLevel = *light->p_lightlevel;
+	}
+	else
+	{
+
+		wall.SectorLightLevel = frontsector->lightlevel;
+	}
+
 	if (!wall.Masked)
 		wall.Render(thread);
 	else