Vrml-Based Slicing Software In Rapid Prototyping

STL (Stereo Lithography) file format, as the most common interface between CAD and RP (Rapid Prototyping) systems, approximates three dimensional solid models with triangular facets. As RP systems become more widely used, disadvantages of STL file become apparent. VRML (Virtual Reality Modeling Language) as an international standard for Virtual Reality has already been widely adopted for graphical representation of 3D objects over the Web. Adopting VRML model in RP can reduce the precision loss caused by triangulation in generating STL file. Models in VRML can be created with geometry, texture and color. Hence exploring a slicing method and software for VRML model is significant to improve the accuracy of RP products, and has good expansibility and adaptability for color RP and virtual manufacturing. Slicing strategy and method suitable for VRML model are proposed based on the analysis of VRML structure. Finding intersections of a plane and VRML model is the key operation in slicing algorithm. To achieve high intersection precision, we calculate plane sections of the geometric primitives (sphere, cylinder and cone) in VRML using solid geometry. With component-based development concept, slicing software for VRML model is developed using VC++ and OpenGL. Practical applications show that the slicing software system based on VRML has high precision and good expansibility.