Abstract: The research on auto-support in stereolithography is carried out. Based on STL model, the method to indentify wait-to-be-supported features is given, by which the wait-to-be-supported surfaces, lines and points can be drawn. The projection areas of wait-to-be-supported features are classified by their geometry characters. Using different filling algorithm arithmetic, these areas are filled with planar supports. The three-point method is used to get the starting point and ending point of supports, and automatic software supporting automatic data generation based on above algorithm is developed. The application shows that this technique can avoid building failures and quality problems when adding supports manually, reduce data processing time and improve the building efficiency.

Key words: Area Identify, Auto-support, Fill arithmetic, Rapid prototyping-manufacture