1 files changed, 1 insertions, 1 deletions
diff --git a/model.cpp b/model.cpp
index 48e714d..98a4ec3 100644
--- a/model.cpp
+++ b/model.cpp
@@ -41,7 +41,7 @@ Model::Model(const QString &filePath)
                 ts >> vertex;
                 const int vertexIndex = vertex.split('/').value(0).toInt();
                 if (vertexIndex)
-                    p.append(vertexIndex - 1);
+                    p.append(vertexIndex > 0 ? vertexIndex - 1 : m_points.size() + vertexIndex);
             }
 
             for (int i = 0; i < p.size(); ++i) {