Merge pull request #916 from wildmeshing/dzint/image_simulation

Fix empty envelope bug after simplification

Author: Spenbert02

components/image_simulation/wmtk/components/image_simulation/EdgeCollapsing.cpp

@@ -389,7 +389,11 @@ void ImageSimulationMesh::simplify()
         m_envelope = nullptr;
         m_V_envelope.clear();
         m_F_envelope.clear();
-        init_envelope(V, F);
+        if (V.size() > 0 && F.size() > 0) {
+            init_envelope(V, F);
+        } else {
+            logger().warn("No surface faces left after simplification, skip re-building envelope");
+        }
     }
     logger().info("===== Simplification done =====");
 }

components/image_simulation/wmtk/components/image_simulation/ImageSimulationMesh.cpp

@@ -586,8 +586,11 @@ void ImageSimulationMesh::init_envelope(const MatrixXd& V, const MatrixXi& F)
     if (m_envelope) {
         log_and_throw_error("Envelope was already initialized once.");
     }
+    if (V.size() == 0 || F.size() == 0) {
+        log_and_throw_error("Envelope vertices and faces cannot be empty.");
+    }
+
     assert(m_V_envelope.empty() && m_F_envelope.empty());
-    assert(V.size() != 0 && F.size() != 0);
     assert(V.cols() == 3); // vertices must be in 3D
     assert(F.cols() == 3); // envelope must be triangles