added alwaysAsOriginal option

src/manifold/src/boolean_result.cpp

@@ -779,38 +779,31 @@
 
 #ifdef MANIFOLD_DEBUG
   triangulate.Stop();
-  Timer simplify;
-  simplify.Start();
+  Timer finish;
+  finish.Start();
 #endif
 
   if (ManifoldParams().intermediateChecks)
     ASSERT(outR.IsManifold(), logicErr, "triangulated mesh is not manifold!");
 
   CreateProperties(outR, inP_, inQ_);
 
-  UpdateReference(outR, inP_, inQ_, invertQ);
-
-  outR.SimplifyTopology();
-
-  if (ManifoldParams().intermediateChecks)
-    ASSERT(outR.Is2Manifold(), logicErr, "simplified mesh is not 2-manifold!");
-
-#ifdef MANIFOLD_DEBUG
-  simplify.Stop();
-  Timer sort;
-  sort.Start();
-#endif
+  if (ManifoldParams().alwaysAsOriginal) {
+    outR.AsOriginal();
+  } else {
+    UpdateReference(outR, inP_, inQ_, invertQ);
+    outR.SimplifyTopology();
+    outR.Finish();
+  }
 
-  outR.Finish();
   outR.IncrementMeshIDs();
 
 #ifdef MANIFOLD_DEBUG
-  sort.Stop();
+  finish.Stop();
   if (ManifoldParams().verbose) {
     assemble.Print("Assembly");
     triangulate.Print("Triangulation");
-    simplify.Print("Simplification");
-    sort.Print("Sorting");
+    finish.Print("Finishing");
     std::cout << outR.NumVert() << " verts and " << outR.NumTri() << " tris"
               << std::endl;
   }

src/manifold/src/edge_op.cpp

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 #include "impl.h"
+#include "optional_assert.h"
 #include "par.h"
 
 namespace {
@@ -256,6 +257,9 @@ void Manifold::Impl::SimplifyTopology() {
     std::cout << "found " << numFlagged << " edges to swap" << std::endl;
   }
 #endif
+
+  if (ManifoldParams().intermediateChecks)
+    ASSERT(Is2Manifold(), logicErr, "simplified mesh is not 2-manifold!");
 }
 
 // Deduplicate the given 4-manifold edge by duplicating endVert, thus making the

src/manifold/src/impl.cpp

@@ -661,6 +661,14 @@ void Manifold::Impl::CreateFaces(const std::vector<float>& propertyTolerance) {
   }
 }
 
+void Manifold::Impl::AsOriginal() {
+  meshRelation_.originalID = ReserveIDs(1);
+  InitializeOriginal();
+  CreateFaces();
+  SimplifyTopology();
+  Finish();
+}
+
 /**
  * Create the halfedge_ data structure from an input triVerts array like Mesh.
  */

src/manifold/src/impl.h

@@ -69,6 +69,7 @@ struct Manifold::Impl {
   void CreateFaces(const std::vector<float>& propertyTolerance = {});
   void RemoveUnreferencedVerts(Vec<glm::ivec3>& triVerts);
   void InitializeOriginal();
+  void AsOriginal();
   void CreateHalfedges(const Vec<glm::ivec3>& triVerts);
   void CalculateNormals();
   void IncrementMeshIDs();

src/manifold/src/manifold.cpp

@@ -438,11 +438,7 @@ int Manifold::OriginalID() const {
  */
 Manifold Manifold::AsOriginal() const {
   auto newImpl = std::make_shared<Impl>(*GetCsgLeafNode().GetImpl());
-  newImpl->meshRelation_.originalID = ReserveIDs(1);
-  newImpl->InitializeOriginal();
-  newImpl->CreateFaces();
-  newImpl->SimplifyTopology();
-  newImpl->Finish();
+  newImpl->AsOriginal();
   return Manifold(std::make_shared<CsgLeafNode>(newImpl));
 }
 

src/utilities/include/public.h

@@ -615,6 +615,10 @@ struct ExecutionParams {
   bool deterministic = false;
   /// Perform optional but recommended triangle cleanups in SimplifyTopology()
   bool cleanupTriangles = true;
+  /// Speed up Boolean operations by resetting each result to an original,
+  /// allowing more simplification to happen, but losing the relationships to
+  /// input meshes.
+  bool alwaysAsOriginal = false;
 };
 
 #ifdef MANIFOLD_DEBUG