Fix ccPolyline ctor keep_alive policy

Author: tmontaigu

script_examples/crop2d.py

@@ -23,7 +23,8 @@
 polyline.addPointIndex(0, vertices.size())
 
 # To see the crop area
-# CC.addToDB(vertices)
+# CC.addToDB(polyline)
+
 
 cropped_ref = pc_to_crop.crop2D(polyline, 2, True)
 if cropped_ref is None:
@@ -34,3 +35,4 @@
     CC.addToDB(cropped)
 else:
     print("No points fall in crop area")
+

wrapper/pycc/src/qcc_db/ccPolyline.cpp

@@ -36,7 +36,9 @@ void define_ccPolyline(py::module &m)
                         unsigned uniqueID = ccUniqueIDGenerator::InvalidUniqueID)
                      { return new ccPolyline(cloud, uniqueID); }),
             "associatedCloud"_a,
-            "uniqueID"_a = []() { return ccUniqueIDGenerator::InvalidUniqueID; }())
+            "uniqueID"_a = []() { return ccUniqueIDGenerator::InvalidUniqueID; }(),
+            py::keep_alive<1, 2>() // Keep cloud alive while polyline is
+            )
 
         .def("set2DMode", &ccPolyline::set2DMode, "state"_a)
         .def("is2DMode", &ccPolyline::is2DMode)