A computer graphic editing or modeling system that automatically alters a computer graphic object based on a user sketch. The computer graphic object may be presented as an image space view of the object (proxy). The sketch is placed in proximity to some feature of the image space view. The system matches the sketch with the feature taking into account silhouettes, which may be derived by way of depth continuity and depth gradient similarity, of the object and matching the silhouette with the feature based on proximity and shape. The matched handle silhouette is transformed to associated handle vertices of a mesh of the graphic object. The system may then deform the mesh based on the user sketch by obtaining a dimensional relationship between the user sketch and the associated silhouette and applying the dimensional relationship to a region of interest, which includes the handle vertices.