diff --git a/include/qbsp/portals.hh b/include/qbsp/portals.hh
index 2aa377eb..7d3f36aa 100644
--- a/include/qbsp/portals.hh
+++ b/include/qbsp/portals.hh
@@ -50,7 +50,13 @@ public:
     bool uses_detail;
 };
 
+struct portalstats_t {
+    std::atomic<int> c_tinyportals;
+};
+
 contentflags_t ClusterContents(const node_t *node);
+void MakeNodePortal(node_t *node, portalstats_t &stats);
+void SplitNodePortals(node_t *node, portalstats_t &stats);
 void MakeTreePortals(tree_t *tree);
 void FreeTreePortals_r(node_t *node);
 void AssertNoPortals(node_t *node);
diff --git a/qbsp/portals.cc b/qbsp/portals.cc
index a6ea2af6..e5f8253a 100644
--- a/qbsp/portals.cc
+++ b/qbsp/portals.cc
@@ -262,10 +262,6 @@ std::optional<winding_t> BaseWindingForNode(node_t *node)
     return w;
 }
 
-struct portalstats_t {
-    std::atomic<int> c_tinyportals;
-};
-
 /*
 ==================
 MakeNodePortal
diff --git a/qbsp/prtfile.cc b/qbsp/prtfile.cc
index 4c8dd0bc..d091c848 100644
--- a/qbsp/prtfile.cc
+++ b/qbsp/prtfile.cc
@@ -28,6 +28,8 @@
 #include <fstream>
 #include <fmt/ostream.h>
 
+#include "tbb/task_group.h"
+
 /*
 ==============================================================================
 
@@ -263,6 +265,27 @@ static void WritePortalfile(node_t *headnode, portal_state_t *state)
     }
 }
 
+/*
+================
+CreateVisPortals_r
+================
+*/
+void CreateVisPortals_r(node_t *node, portalstats_t &stats)
+{
+    // stop as soon as we get to a detail_seperator, which
+    // means that everything below is in a single cluster
+    if (node->planenum == PLANENUM_LEAF || node->detail_separator )
+        return;
+
+    MakeNodePortal(node, stats);
+    SplitNodePortals(node, stats);
+
+    tbb::task_group g;
+    g.run([&]() { CreateVisPortals_r(node->children[0], stats); });
+    g.run([&]() { CreateVisPortals_r(node->children[1], stats); });
+    g.wait();
+}
+
 /*
 ==================
 WritePortalFile