Remove CreateFaces entirely

.vscode/launch.json

@@ -13,6 +13,7 @@
       "args": [
         "--gtest_break_on_failure",
         "--gtest_catch_exceptions=0",
+        "--gtest_filter=Boolean.Cubes"
       ],
       "stopAtEntry": false,
       "cwd": "${workspaceFolder}/build/test",
@@ -25,4 +26,4 @@
       "externalConsole": false
     }
   ]
-}
+}

bindings/python/manifold3d.cpp

@@ -350,9 +350,7 @@ NB_MODULE(manifold3d, m) {
           "Get the surface area of the manifold\n This is clamped to zero for "
           "a given face if they are within the Precision().")
       .def("original_id", &Manifold::OriginalID, manifold__original_id)
-      .def("as_original", &Manifold::AsOriginal,
-           nb::arg("property_tolerance") = nb::list(),
-           manifold__as_original__property_tolerance)
+      .def("as_original", &Manifold::AsOriginal, manifold__as_original)
       .def("is_empty", &Manifold::IsEmpty, manifold__is_empty)
       .def("decompose", &Manifold::Decompose, manifold__decompose)
       .def("split", &Manifold::Split, nb::arg("cutter"),

include/manifold/manifold.h

@@ -78,13 +78,10 @@ struct MeshGLP {
   /// This matrix is stored in column-major order and the length of the overall
   /// vector is 12 * runOriginalID.size().
   std::vector<Precision> runTransform;
-  /// Optional: Length NumTri, contains an ID of the source face this triangle
-  /// comes from. When auto-generated, this ID will be a triangle index into the
-  /// original mesh. All neighboring coplanar triangles from that input mesh
-  /// will refer to a single triangle of that group as the faceID. When
-  /// supplying faceIDs, ensure that triangles with the same ID are in fact
-  /// coplanar and have consistent properties (within some tolerance) or the
-  /// output will be surprising.
+  /// Optional: Length NumTri, contains the source face ID this
+  /// triangle comes from. When auto-generated, this ID will be a triangle index
+  /// into the original mesh. This index/ID is purely for external use (e.g.
+  /// recreating polygonal faces) and will not affect Manifold's algorithms.
   std::vector<I> faceID;
   /// Optional: The X-Y-Z-W weighted tangent vectors for smooth Refine(). If
   /// non-empty, must be exactly four times as long as Mesh.triVerts. Indexed
@@ -246,7 +243,7 @@ class Manifold {
    */
   ///@{
   int OriginalID() const;
-  Manifold AsOriginal(const std::vector<double>& propertyTolerance = {}) const;
+  Manifold AsOriginal() const;
   static uint32_t ReserveIDs(uint32_t);
   ///@}
 

src/constructors.cpp

@@ -53,7 +53,9 @@ Manifold Manifold::Smooth(const MeshGL& meshGL,
                "rather than Smooth().");
 
   std::shared_ptr<Impl> impl = std::make_shared<Impl>(meshGL);
-  impl->CreateTangents(impl->UpdateSharpenedEdges(sharpenedEdges));
+  const Vec<bool> internalEdges = impl->InternalEdges();
+  impl->CreateTangents(impl->UpdateSharpenedEdges(sharpenedEdges),
+                       internalEdges);
   return Manifold(impl);
 }
 
@@ -92,7 +94,9 @@ Manifold Manifold::Smooth(const MeshGL64& meshGL64,
                "rather than Smooth().");
 
   std::shared_ptr<Impl> impl = std::make_shared<Impl>(meshGL64);
-  impl->CreateTangents(impl->UpdateSharpenedEdges(sharpenedEdges));
+  const Vec<bool> internalEdges = impl->InternalEdges();
+  impl->CreateTangents(impl->UpdateSharpenedEdges(sharpenedEdges),
+                       internalEdges);
   return Manifold(impl);
 }
 
@@ -274,7 +278,6 @@ Manifold Manifold::Extrude(const Polygons& crossSection, double height,
   pImpl_->CreateHalfedges(triVertsDH);
   pImpl_->Finish();
   pImpl_->InitializeOriginal();
-  pImpl_->CreateFaces();
   return Manifold(pImpl_);
 }
 
@@ -418,7 +421,6 @@ Manifold Manifold::Revolve(const Polygons& crossSection, int circularSegments,
   pImpl_->CreateHalfedges(triVertsDH);
   pImpl_->Finish();
   pImpl_->InitializeOriginal();
-  pImpl_->CreateFaces();
   return Manifold(pImpl_);
 }
 

src/edge_op.cpp

@@ -58,27 +58,6 @@ struct ShortEdge {
   }
 };
 
-struct FlagEdge {
-  VecView<const Halfedge> halfedge;
-  VecView<const TriRef> triRef;
-
-  bool operator()(int edge) const {
-    if (halfedge[edge].pairedHalfedge < 0) return false;
-    // Flag redundant edges - those where the startVert is surrounded by only
-    // two original triangles.
-    const TriRef ref0 = triRef[edge / 3];
-    int current = NextHalfedge(halfedge[edge].pairedHalfedge);
-    const TriRef ref1 = triRef[current / 3];
-    while (current != edge) {
-      current = NextHalfedge(halfedge[current].pairedHalfedge);
-      int tri = current / 3;
-      const TriRef ref = triRef[tri];
-      if (!ref.SameFace(ref0) && !ref.SameFace(ref1)) return false;
-    }
-    return true;
-  }
-};
-
 struct SwappableEdge {
   VecView<const Halfedge> halfedge;
   VecView<const vec3> vertPos;
@@ -227,10 +206,19 @@ void Manifold::Impl::SimplifyTopology() {
 
   {
     ZoneScopedN("CollapseFlaggedEdge");
+    const Vec<bool> internalEdges = InternalEdges();
     numFlagged = 0;
-    FlagEdge se{halfedge_, meshRelation_.triRef};
     for_each_n(policy, countAt(0_uz), nbEdges,
-               [&](size_t i) { bFlags[i] = se(i); });
+               [this, &internalEdges, &bFlags](size_t edge) {
+                 if (halfedge_[edge].pairedHalfedge < 0) return;
+                 // Flag redundant edges - those where the startVert is
+                 // surrounded by only two original triangles.
+                 int numExternal = internalEdges[edge] ? 2 : 0;
+                 ForVert(edge, [&numExternal, &internalEdges](int current) {
+                   numExternal += internalEdges[current] ? 0 : 1;
+                 });
+                 bFlags[edge] = numExternal < 3;
+               });
     for (size_t i = 0; i < nbEdges; ++i) {
       if (bFlags[i]) {
         CollapseEdge(i, scratchBuffer);
@@ -484,30 +472,26 @@ void Manifold::Impl::CollapseEdge(const int edge, std::vector<int>& edges) {
   int start = halfedge_[tri1edge[1]].pairedHalfedge;
   if (!shortEdge) {
     current = start;
-    TriRef refCheck = triRef[toRemove.pairedHalfedge / 3];
+    int numExternal = Internal(edge) ? 2 : 1;
+    numExternal += Internal(tri1edge[1]) ? 0 : 1;
     vec3 pLast = vertPos_[halfedge_[tri1edge[1]].endVert];
     while (current != tri0edge[2]) {
       current = NextHalfedge(current);
-      vec3 pNext = vertPos_[halfedge_[current].endVert];
-      const int tri = current / 3;
-      const TriRef ref = triRef[tri];
-      const mat3x2 projection = GetAxisAlignedProjection(faceNormal_[tri]);
+
       // Don't collapse if the edge is not redundant (this may have changed due
-      // to the collapse of neighbors).
-      if (!ref.SameFace(refCheck)) {
-        refCheck = triRef[edge / 3];
-        if (!ref.SameFace(refCheck)) {
-          return;
-        } else {
-          // Don't collapse if the edges separating the faces are not colinear
-          // (can happen when the two faces are coplanar).
-          if (CCW(projection * pOld, projection * pLast, projection * pNew,
-                  precision_) != 0)
-            return;
-        }
-      }
+      //  to the collapse of neighbors).
+      numExternal += Internal(current) ? 0 : 1;
+      if (numExternal > 2) return;
 
       // Don't collapse edge if it would cause a triangle to invert.
+      const vec3 pNext = vertPos_[halfedge_[current].endVert];
+      const mat3x2 projection =
+          GetAxisAlignedProjection(faceNormal_[current / 3]);
+      // Don't collapse if the edges separating the faces are not colinear
+      // (can happen when the two faces are coplanar).
+      if (CCW(projection * pOld, projection * pLast, projection * pNew,
+              precision_) != 0)
+        return;
       if (CCW(projection * pNext, projection * pLast, projection * pNew,
               precision_) < 0)
         return;
@@ -534,9 +518,9 @@ void Manifold::Impl::CollapseEdge(const int edge, std::vector<int>& edges) {
       // Update the shifted triangles to the vertBary of endVert
       const int tri = current / 3;
       const int vIdx = current - 3 * tri;
-      if (triRef[tri].SameFace(triRef[tri0])) {
+      if (triProp[tri][vIdx] == triProp[tri0][Prev3(triVert0)]) {
         triProp[tri][vIdx] = triProp[tri0][triVert0];
-      } else if (triRef[tri].SameFace(triRef[tri1])) {
+      } else if (triProp[tri][vIdx] == triProp[tri1][Next3(triVert1)]) {
         triProp[tri][vIdx] = triProp[tri1][triVert1];
       }
     }