Fix calculation of projection direction in project()

src/build123d/operations_generic.py

@@ -771,8 +771,7 @@ def project(
     projected_shapes = []
     obj: Shape
     for obj in face_list + line_list:
-        obj_to_screen = (target.center() - obj.center()).normalized()
-        if workplane.from_local_coords(obj_to_screen).Z < 0:
+        if workplane.to_local_coords(obj.center()).Z > 0:
             projection_direction = -workplane.z_dir * projection_flip
         else:
             projection_direction = workplane.z_dir * projection_flip
@@ -790,7 +789,7 @@ def project(
     projected_points = []
     for pnt in point_list:
         pnt_to_target = (workplane.origin - pnt).normalized()
-        if workplane.from_local_coords(pnt_to_target).Z < 0:
+        if workplane.to_local_coords(pnt_to_target).Z < 0:
             projection_axis = -Axis(pnt, workplane.z_dir * projection_flip)
         else:
             projection_axis = Axis(pnt, workplane.z_dir * projection_flip)

src/build123d/topology.py

@@ -6043,6 +6043,9 @@ def project_to_shape(
         for target_face in target_object.faces():
             intersected_faces.extend(face_extruded.intersect(target_face).faces())
 
+        if len(intersected_faces) == 0:
+            return ShapeList()
+
         # intersected faces may be fragmented so we'll put them back together
         sewed_face_list = Face.sew_faces(intersected_faces)
         sewed_faces = ShapeList()

tests/test_build_generic.py

@@ -665,7 +665,7 @@ def test_project_to_sketch1(self):
     def test_project_to_sketch2(self):
         with BuildPart() as test2:
             Box(4, 4, 1)
-            with BuildSketch(Plane.XY.offset(0.1)) as c:
+            with BuildSketch(Plane.XY.offset(2)) as c:
                 Rectangle(1, 1)
             project()
             extrude(amount=1)