Breaking the Rules of Visual Perception

Steve Visser, Zhenyu Cheryl Qian
Purdue University


Steve Visser / Zhenyu Cheryl Qian
Purdue University

In identifying a design consumers rely upon three major factors. These factors allow them to understand the form of products. First, is the profile or silhouette of the product. The profile is the outside contour of a product.  Secondly, are the details of a product.  The details help the observer distinguish even more precisely one design from another. Details include the shapes of distinct parts, segments, as well as added or subtracted portions such as holes or appendages. Finally, the topography of the surfaces helps the observer perceive the form of a product. The surface topography includes; contours, dips, and undulations in the surface. Contours in the surface are seen in the highlights and shadows that help one understand the form of an object. 

People don’t typically think about how they perceive or identify an object, they just do it intuitively.  As designers it is important for us to understand how consumers view and identify products.  Designers need to have an understanding of how their design decisions they make affect the perception of the consumer.  

Once it is understood how people perceive the form of an object, the designer can take advantage of this and “break the rules of perception” to make a product look thinner than it actually is, or make the product appear more delicate or strong. This paper will be an exploration of how the designer can change the silhouette, details and surfaces to impact the perception of the design. How do fillets, chamfers, part-lines and style-lines impact the perception of the product?  The paper will include deconstructions of existing products as well as simple CAD drawings to explain the concepts.