Computer programs and computer-implemented methods implement techniques for creating and manipulating related vector objects in an image. These include creating a first vector object or elements in an image, creating a second vector object or elements in the image, and in response to creating the second vector object(s) in the image, calculating one or more new values for a first attribute of the one or more attributes for the first vector object(s) based at least in part on one or more of the current attribute values for the second vector object(s).Relationships are defined between vector objects using equations that define a value (or values) for an attribute for one vector object or elements as a function of attribute value(s) defined for the same or different vector objects in the image. In preferred embodiments, the function includes equations defining an attractive force and a repulsive force between the attribute value(s).