Abstract: Visual stimuli provided by surfaces of an object are selected based on anticipated viewing angles and activities associated with the viewing angles. Such surfaces can be selected based on identification and observation of significant events in a selected activity. Object zones so identified can be provided with functional ornamentation to enhance performance of one or more activities. Functional ornamentation can be based on gray level contrast, color contrast, or other visual characteristics. Dynamic functional ornamentation in which visual characteristics are a function of ornamentation motion, placement, distortion, of viewing angle can be used. In some examples, almost periodic patterns can be used, and the almost periodic patterns defined with a plurality of tiles.