What is the difference between CAS surface and A surface?

[DavidDella]

Here is an introduction to the differences between CAS surface and A surface: The sequence is different: In automotive styling, the A surface comes first, followed by the CAS surface. Before the release of the automotive styling A surface, the digital model used for preliminary display of the interior and exterior styling is called the CAS surface. The content they represent is different: The A surface must meet the requirements of a gap between adjacent surfaces of less than 0.005mm, a tangent change of less than 0.16 degrees, and a curvature change of less than 0.005 degrees. On the other hand, the CAS surface is mainly used in the styling feasibility study phase for checking regulatory requirements, styling, engineering, production, after-sales maintenance, insurance services, and the production of small-scale clay models.