fixed precision bug for compose/decompose

elalish · Jun 5, 2022 · 19dc9de · 19dc9de
1 parent b31baa6
commit 19dc9de
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Showing 3 changed files with 16 additions and 1 deletion.
diff --git a/manifold/src/constructors.cpp b/manifold/src/constructors.cpp
@@ -415,6 +415,8 @@ std::vector<Manifold> Manifold::Decompose() const {
   std::vector<Manifold> meshes;
   for (int i = 0; i < numLabel; ++i) {
     auto impl = std::make_shared<Impl>();
+    // inherit original object's precision
+    impl->precision_ = pImpl_->precision_;
     impl->vertPos_.resize(NumVert());
     VecDH<int> vertNew2Old(NumVert());
     auto policy = autoPolicy(NumVert());

diff --git a/manifold/src/csg_tree.cpp b/manifold/src/csg_tree.cpp
@@ -115,18 +115,29 @@ CsgNodeType CsgLeafNode::GetNodeType() const { return CsgNodeType::LEAF; }
  */
 Manifold::Impl CsgLeafNode::Compose(
     const std::vector<std::shared_ptr<CsgLeafNode>> &nodes) {
+  float precision = -1;
   int numVert = 0;
   int numEdge = 0;
   int numTri = 0;
   int numBary = 0;
   for (auto &node : nodes) {
+    float nodeOldScale = node->pImpl_->bBox_.Scale();
+    float nodeNewScale = node->GetBoundingBox().Scale();
+    float nodePrecision = node->pImpl_->precision_;
+    nodePrecision *= glm::max(1.0f, nodeNewScale / nodeOldScale);
+    nodePrecision = glm::max(nodePrecision, kTolerance * nodeNewScale);
+    if (!glm::isfinite(nodePrecision))
+      nodePrecision = -1;
+    precision = glm::max(precision, nodePrecision);
+
     numVert += node->pImpl_->NumVert();
     numEdge += node->pImpl_->NumEdge();
     numTri += node->pImpl_->NumTri();
     numBary += node->pImpl_->meshRelation_.barycentric.size();
   }
 
   Manifold::Impl combined;
+  combined.precision_ = precision;
   combined.vertPos_.resize(numVert);
   combined.halfedge_.resize(2 * numEdge);
   combined.faceNormal_.resize(numTri);
@@ -194,6 +205,8 @@ Manifold::Impl CsgLeafNode::Compose(
     nextTri += node->pImpl_->NumTri();
     nextBary += node->pImpl_->meshRelation_.barycentric.size();
   }
+  // required to remove parts that are smaller than the precision
+  combined.SimplifyTopology();
   combined.Finish();
   return combined;
 }

diff --git a/manifold/src/impl.cpp b/manifold/src/impl.cpp
@@ -561,7 +561,7 @@ Manifold::Impl Manifold::Impl::Transform(const glm::mat4x3 &transform_) const {
   result.precision_ *= glm::max(1.0f, newScale / oldScale);
 
   // Maximum of inherited precision loss and translational precision loss.
-  result.SetPrecision(precision_);
+  result.SetPrecision(result.precision_);
   return result;
 }