diff --git a/generate_cpp.py b/generate_cpp.py
index 9bd1e75..abc5375 100644
--- a/generate_cpp.py
+++ b/generate_cpp.py
@@ -32,14 +32,26 @@ def generate_faces(group_name, model_name, faces, type, n):
         yield "}},"
     yield "};"
 
+def generate_lines(group_name, model_name, lines, type, n):
+    yield f"const union {type} {group_name}_{model_name}_{type}[] = {{"
+    for line in lines:
+        yield "{"
+        yield f".a = {line.a},"
+        yield f".b = {line.b},"
+        yield "},"
+    yield "};"
+
 def generate_object(group_name, object):
     yield f"const struct object {group_name}_{object.name} = {{"
     yield f".triangle = &{group_name}_{object.name}_triangle[0],"
     yield f".quadrilateral = &{group_name}_{object.name}_quadrilateral[0],"
+    yield f".line = &{group_name}_{object.name}_line[0],"
     triangle_count = sum(1 for _ in filter_n(object.faces, 3))
     quadrilateral_count = sum(1 for _ in filter_n(object.faces, 4))
+    line_count = len(object.lines)
     yield f".triangle_count = {triangle_count},"
     yield f".quadrilateral_count = {quadrilateral_count},"
+    yield f".line_count = {line_count},"
     if object.material is None:
         yield ".material = 0,"
     else:
@@ -74,6 +86,7 @@ def generate_obj_file(group_name, obj_file):
         assert all(len(face.ptn) in {3, 4} for face in object.faces), object.name
         yield from generate_faces(group_name, object.name, object.faces, "triangle", 3)
         yield from generate_faces(group_name, object.name, object.faces, "quadrilateral", 4)
+        yield from generate_lines(group_name, object.name, object.lines, "line", 4)
         yield from generate_object(group_name, object)
 
     yield from generate_object_array(group_name, obj_file)
diff --git a/obj.py b/obj.py
index e77b3bb..87daa7c 100644
--- a/obj.py
+++ b/obj.py
@@ -46,6 +46,11 @@ class FacePTN:
 class Face:
     ptn: list[FacePTN]
 
+@dataclass
+class Line:
+    a: int
+    b: int
+
 @dataclass
 class Material:
     name: str
@@ -54,11 +59,13 @@ class Material:
 class Object:
     name: str
     faces: list[Face]
+    lines: list[Line]
     material: Material
 
-    def __init__(self, name, faces=None, material=None):
+    def __init__(self, name, faces=None, lines=None, material=None):
         self.name = name
         self.faces = [] if faces is None else faces
+        self.lines = [] if lines is None else lines
         self.material = material
 
 @dataclass
@@ -124,6 +131,12 @@ def parse_usemtl(line):
     name, = line
     return Material(name)
 
+def parse_polyline(line):
+    assert len(line) == 2
+    a, b = line
+    return Line(int(a, 10) - 1,
+                int(b, 10) - 1)
+
 def parse_line(line):
     t, *line = line.split(' ')
     if t == '#':
@@ -147,7 +160,7 @@ def parse_line(line):
         return None
     if t == 'l':
         # polyline
-        return None
+        return parse_polyline(line)
     assert False, (t, line)
 
 def parse_obj_lines(lines):
@@ -175,9 +188,11 @@ def parse_obj_lines(lines):
                 file.objects.append(object)
                 object = Object(object.name + "_mtl_" + x.name)
             object.material = x
+        elif type(x) is Line:
+            object.lines.append(x)
         else:
             assert False, x
-    if object.faces:
+    if object.faces or object.lines:
         assert object.name != None
         file.objects.append(object)
     return file