Attempt a simple rebuild of PolySet on Manifold error (openscad#5183)

schiele · Jun 23, 2024 · 9b9adab · 9b9adab
1 parent 9eb0202
commit 9b9adab
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Showing 6 changed files with 40 additions and 1 deletion.
diff --git a/src/geometry/manifold/manifoldutils.cc b/src/geometry/manifold/manifoldutils.cc
@@ -1,6 +1,7 @@
 // Portions of this file are Copyright 2023 Google LLC, and licensed under GPL2+. See COPYING.
 #include "manifoldutils.h"
 #include "ManifoldGeometry.h"
+#include "PolySetBuilder.h"
 #include "manifold.h"
 #include "printutils.h"
 #ifdef ENABLE_CGAL
@@ -113,7 +114,23 @@ std::shared_ptr<ManifoldGeometry> createManifoldFromPolySet(const PolySet& ps)
     return mani;
   }
 
-  // FIXME: Should we suppress this warning, as it may not be very actionable?
+  // Before announcing that the conversion failed, let's try to fix the most common
+  // causes of a non-manifold topology:
+  // Polygon soup of manifold topology with co-incident vertices having identical vertex positions
+  //
+  // Note: This causes us to lose the ability to represent manifold topologies with duplicate 
+  // vertex positions (touching cubes, donut with vertex in the center etc.)
+  PolySetBuilder builder(ps.vertices.size(), ps.indices.size(),
+                         ps.getDimension(), ps.convexValue());
+  builder.appendPolySet(ps);
+  std::unique_ptr<PolySet> rebuilt_ps = builder.build();
+  rebuilt_ps->setTriangular(ps.isTriangular());
+  mani = createManifoldFromTriangularPolySet(*rebuilt_ps);
+  if (mani->getManifold().Status() == Error::NoError) {
+    return mani;
+  }
+
+  // FIXME: Should we attempt merging vertices within epsilon distance before issuing this warning?
   LOG(message_group::Warning,"PolySet -> Manifold conversion failed: %1$s\n"
       "Trying to repair and reconstruct mesh..",
       ManifoldUtils::statusToString(mani->getManifold().Status()));

diff --git a/tests/data/scad/3D/features/polyhedron-soup.scad b/tests/data/scad/3D/features/polyhedron-soup.scad
@@ -0,0 +1,20 @@
+polyhedron(points = [
+ [1,0,0], [0,0,1], [0,1,0],
+ [1,0,0], [0,1,0], [0,0,-1],
+ [1,0,0], [0,-1,0], [0,0,1],
+ [1,0,0], [0,0,-1], [0,-1,0],
+ [-1,0,0], [0,1,0], [0,0,1],
+ [-1,0,0], [0,0,-1], [0,1,0],
+ [-1,0,0], [0,0,1], [0,-1,0],
+ [-1,0,0], [0,-1,0], [0,0,-1],
+],
+faces = [
+ [0,1,2],
+ [3,4,5],
+ [6,7,8],
+ [9,10,11],
+ [12,13,14],
+ [15,16,17],
+ [18,19,20], 
+ [21,22,23]
+]);
diff --git a/tests/regression/cgalpngtest/polyhedron-soup-expected.png b/tests/regression/cgalpngtest/polyhedron-soup-expected.png
diff --git a/tests/regression/dumptest/polyhedron-soup-expected.csg b/tests/regression/dumptest/polyhedron-soup-expected.csg
@@ -0,0 +1,2 @@
+polyhedron(points = [[1, 0, 0], [0, 0, 1], [0, 1, 0], [1, 0, 0], [0, 1, 0], [0, 0, -1], [1, 0, 0], [0, -1, 0], [0, 0, 1], [1, 0, 0], [0, 0, -1], [0, -1, 0], [-1, 0, 0], [0, 1, 0], [0, 0, 1], [-1, 0, 0], [0, 0, -1], [0, 1, 0], [-1, 0, 0], [0, 0, 1], [0, -1, 0], [-1, 0, 0], [0, -1, 0], [0, 0, -1]], faces = [[0, 1, 2], [3, 4, 5], [6, 7, 8], [9, 10, 11], [12, 13, 14], [15, 16, 17], [18, 19, 20], [21, 22, 23]], convexity = 1);
+
diff --git a/tests/regression/opencsgtest/polyhedron-soup-expected.png b/tests/regression/opencsgtest/polyhedron-soup-expected.png
diff --git a/tests/regression/throwntogethertest/polyhedron-soup-expected.png b/tests/regression/throwntogethertest/polyhedron-soup-expected.png
Original file line number	Diff line number	Diff line change
		@@ -0,0 +1,2 @@
		polyhedron(points = [[1, 0, 0], [0, 0, 1], [0, 1, 0], [1, 0, 0], [0, 1, 0], [0, 0, -1], [1, 0, 0], [0, -1, 0], [0, 0, 1], [1, 0, 0], [0, 0, -1], [0, -1, 0], [-1, 0, 0], [0, 1, 0], [0, 0, 1], [-1, 0, 0], [0, 0, -1], [0, 1, 0], [-1, 0, 0], [0, 0, 1], [0, -1, 0], [-1, 0, 0], [0, -1, 0], [0, 0, -1]], faces = [[0, 1, 2], [3, 4, 5], [6, 7, 8], [9, 10, 11], [12, 13, 14], [15, 16, 17], [18, 19, 20], [21, 22, 23]], convexity = 1);