diff -r 764381756899 -r 62373840e33a src/linetypes/object.h
--- a/src/linetypes/object.h	Wed Mar 11 19:05:34 2020 +0200
+++ b/src/linetypes/object.h	Tue Mar 17 23:13:29 2020 +0200
@@ -81,6 +81,9 @@
 		PropertyNotHandled,
 		InvalidValue
 	};
+	class BadPointIndex : public std::exception
+	{
+	};
 	Object();
 	Object(const Object&) = delete;
 	virtual ~Object();
@@ -95,6 +98,8 @@
 	virtual QFont textRepresentationFont() const;
 	virtual void getPolygons(std::vector<gl::Polygon>& polygons, GetPolygonsContext* context) const;
 	virtual void invert() {}
+	virtual int numPoints() const { return 0; }
+	virtual const glm::vec3& getPoint(int index) const;
 };
 
 class ldraw::ColoredObject : public Object