diff --git a/DebugUtils/Source/RecastDebugDraw.cpp b/DebugUtils/Source/RecastDebugDraw.cpp
index b1a57ef..82050bd 100644
--- a/DebugUtils/Source/RecastDebugDraw.cpp
+++ b/DebugUtils/Source/RecastDebugDraw.cpp
@@ -806,24 +806,23 @@ void duDebugDrawContours(duDebugDraw* dd, const rcContourSet& cset, const float
 		const rcContour& c = cset.conts[i];
 		if (!c.nverts)
 			continue;
-		unsigned int color = duIntToCol(c.reg, a);
-
-		for (int j = 0; j < c.nverts; ++j)
+		const unsigned int color = duIntToCol(c.reg, a);
+		const unsigned int bcolor = duLerpCol(color,duRGBA(255,255,255,a),128);
+		for (int j = 0, k = c.nverts-1; j < c.nverts; k=j++)
 		{
-			const int* v = &c.verts[j*4];
-			float fx = orig[0] + v[0]*cs;
-			float fy = orig[1] + (v[1]+1+(i&1))*ch;
-			float fz = orig[2] + v[2]*cs;
-			dd->vertex(fx,fy,fz, color);
-			if (j > 0)
-				dd->vertex(fx,fy,fz, color);
+			const int* va = &c.verts[k*4];
+			const int* vb = &c.verts[j*4];
+			unsigned int col = (va[3] & RC_AREA_BORDER) ? bcolor : color; 
+			float fx,fy,fz;
+			fx = orig[0] + va[0]*cs;
+			fy = orig[1] + (va[1]+1+(i&1))*ch;
+			fz = orig[2] + va[2]*cs;
+			dd->vertex(fx,fy,fz, col);
+			fx = orig[0] + vb[0]*cs;
+			fy = orig[1] + (vb[1]+1+(i&1))*ch;
+			fz = orig[2] + vb[2]*cs;
+			dd->vertex(fx,fy,fz, col);
 		}
-		// Loop last segment
-		const int* v = &c.verts[0];
-		float fx = orig[0] + v[0]*cs;
-		float fy = orig[1] + (v[1]+1+(i&1))*ch;
-		float fz = orig[2] + v[2]*cs;
-		dd->vertex(fx,fy,fz, color);
 	}
 	dd->end();
 
diff --git a/Recast/Source/RecastContour.cpp b/Recast/Source/RecastContour.cpp
index 5d58e52..5c324bc 100644
--- a/Recast/Source/RecastContour.cpp
+++ b/Recast/Source/RecastContour.cpp
@@ -464,7 +464,7 @@ static void simplifyContour(rcIntArray& points, rcIntArray& simplified,
 		// and the neighbour region is take from the next raw point.
 		const int ai = (simplified[i*4+3]+1) % pn;
 		const int bi = simplified[i*4+3];
-		simplified[i*4+3] = (points[ai*4+3] & RC_CONTOUR_REG_MASK) | (points[bi*4+3] & RC_BORDER_VERTEX);
+		simplified[i*4+3] = (points[ai*4+3] & (RC_CONTOUR_REG_MASK|RC_AREA_BORDER)) | (points[bi*4+3] & RC_BORDER_VERTEX);
 	}
 	
 }
diff --git a/Recast/Source/RecastMesh.cpp b/Recast/Source/RecastMesh.cpp
index 012115f..2310e34 100644
--- a/Recast/Source/RecastMesh.cpp
+++ b/Recast/Source/RecastMesh.cpp
@@ -934,10 +934,18 @@ bool rcBuildPolyMesh(rcContext* ctx, rcContourSet& cset, const int nvp, rcPolyMe
 	rcScopedDelete<unsigned char> vflags = (unsigned char*)rcAlloc(sizeof(unsigned char)*maxVertices, RC_ALLOC_TEMP);
 	if (!vflags)
 	{
-		ctx->log(RC_LOG_ERROR, "rcBuildPolyMesh: Out of memory 'mesh.verts' (%d).", maxVertices);
+		ctx->log(RC_LOG_ERROR, "rcBuildPolyMesh: Out of memory 'vflags' (%d).", maxVertices);
 		return false;
 	}
 	memset(vflags, 0, maxVertices);
+
+	rcScopedDelete<unsigned short> vportal = (unsigned short*)rcAlloc(sizeof(unsigned short)*maxVertices, RC_ALLOC_TEMP);
+	if (!vportal)
+	{
+		ctx->log(RC_LOG_ERROR, "rcBuildPolyMesh: Out of memory 'vportal' (%d).", maxVertices);
+		return false;
+	}
+	memset(vportal, 0xff, maxVertices);
 	
 	mesh.verts = (unsigned short*)rcAlloc(sizeof(unsigned short)*maxVertices*3, RC_ALLOC_PERM);
 	if (!mesh.verts)
@@ -1053,6 +1061,14 @@ bool rcBuildPolyMesh(rcContext* ctx, rcContourSet& cset, const int nvp, rcPolyMe
 				vflags[indices[j]] = 1;
 			}
 		}
+
+		// Store portal edges
+		for (int j = 0; j < cont.nverts; ++j)
+		{
+			const int* v = &cont.verts[j*4];
+			if ((v[3] & RC_AREA_BORDER) == 0)
+				vportal[indices[j]] = indices[(j+1) % cont.nverts];
+		}
 		
 		// Build initial polygons.
 		int npolys = 0;
@@ -1150,8 +1166,17 @@ bool rcBuildPolyMesh(rcContext* ctx, rcContourSet& cset, const int nvp, rcPolyMe
 			}
 			// Remove vertex
 			// Note: mesh.nverts is already decremented inside removeVertex()!
+			// Fixup vertex flags
 			for (int j = i; j < mesh.nverts; ++j)
 				vflags[j] = vflags[j+1];
+			// Fixup portal indices
+			for (int j = i; j < mesh.nverts; ++j)
+				vportal[j] = vportal[j+1];
+			for (int j = 0; j < mesh.nverts; ++j)
+			{
+				if (vportal[j] > (unsigned short)i)
+					vportal[j]--;
+			}
 			--i;
 		}
 	}
@@ -1182,6 +1207,10 @@ bool rcBuildPolyMesh(rcContext* ctx, rcContourSet& cset, const int nvp, rcPolyMe
 				const unsigned short* va = &mesh.verts[p[j]*3];
 				const unsigned short* vb = &mesh.verts[p[nj]*3];
 
+				// Make sure the edge is marked as portal.
+				if (vportal[p[j]] != p[nj])
+					continue;
+
 				if ((int)va[0] == 0 && (int)vb[0] == 0)
 					p[nvp+j] = 0x8000 | 0;
 				else if ((int)va[2] == h && (int)vb[2] == h)