ABSTRACT
The internet is full of three-dimensional (3D) printing applications for children, like Crayon Creatures that turns children’s' drawings into 3D printed figurines or Cookie Caster for building custom cookie cutters from existing images. In general, 3D modelling programs are divided into five categories: solid modelling, sculpting modelling, polygonal modelling, parametric design, and vector-graphic design programs, although some programs may be a hybrid of techniques. If there is one most vital design consideration for 3D printing, it would be the issue of manifold integrity. Having a manifold model enables the printing software to understand what the inside is and what is the outside of a model is in order to comprehend how to print the object properly. Each part of the model must be extruded as separate, manifold standard tessellation language files, but aligned in the printer software to print as one object.
