1. A computer implemented method for manipulating a graphical representation of a real-world object in a computer drawing application comprising: (a) defining, using a computer, a semantic behavior for the real-world object, wherein: (i) the semantic behavior comprises a collision rule, an orientation rule, an affinity rule, and an attachment rule; (ii) the collision rule defines an intersection between geometries or bounding boxes of a subject object and a host object; (iii) the orientation rule defines an alignment of the subject object with a geometry of the host object; (iv) the affinity rule defines placement rules that determine where the subject object can be legally placed in a drawing; (v) the attachment rule defines an attachment between the subject object and the host object wherein both the subject object and the host object move if either the host object or subject object is moved; (vi) the affinity rule has procedural priority over the orientation rule; (vii) the attachment rule has procedural priority over the affinity rule and the orientation rule; and (viii) the collision rule has procedural priority over the attachment rule, the affinity rule, and the orientation rule; (b) obtaining, using a computer, a graphical representation of the real-world object, wherein the graphical representation is referred to as the subject object; (c) assigning, using a computer, the semantic behavior to the subject object, wherein: (i) the semantic behavior defines a behavioral rule for placement of the subject object into the drawing; (ii) the behavioral rule specifies a host object type that specifies a type of object that the behavioral rule applies to; (iii) the behavioral rule specifies an exclusion host identifier that identifies a particular host object for which an application of the behavioral rule will be excluded; and (d) placing, using a computer, the subject object into the drawing using the computer-drawing application, wherein the subject object automatically, without additional user input, places itself into the drawing based on the semantic behavior.