In design expression stage, product three-dimensional
design expression effect picture is obtained by rendering,
textures, lighting, cameras, simulation light computation and so
on. This decides the texture feeling and final effect of the
product. As shown in Figure 5, the most important aspect of
product design expression is accuracy. Product design
expression should express product accurate imformation and
let people understand the product correctly. So product design
expression should faithfully express the shape, color, texture
and structure of product.