Designing Playground Equipment with VR and 3D printing

Abstract

Designing objects in 3D is usually performed in CAD programs, which show the 3D object on a 2D screen. This has a disconnect with the final real world object that can be walked around and interacted with. To bridge the gap between design and the real world result, virtual reality can be used in conjunction with 3D printing. Converting models made in virtual reality to 3D prints is not straightforward, as prints have to show a number of desired properties. Previous studies show that these properties are: (1) it should consist of one connected component that touches the printing platform, (2) it should be able to stand without falling over and (3) it should be structurally sound. A program has been implemented that analyzes these properties on models made in VR. This is the first 3D print analysis program that works in virtual reality. To test the effectiveness of the program we asked 35 elementary school children to design playground equipment in Google Blocks. Then these designs where 3D printed and tested for desired properties. Our program analyzed the connectedness 92.9\% of the time, the balance 100\% of the time and the strength of the print 50\% of the time. This shows that computing vertex connectivity, component intersection, convex hull and the center of mass is sufficient to objects with the first and second property in most cases, but we can not conclude that it is sufficient in all cases. We used a limited sample size of 16 models, so edge cases could exist where this functionality is not sufficient. However, we can conclude that thin area detection is not enough to successfully analyze strength in all models. While further research is needed to draw more conclusions, this is a good first step in gaining understanding of the correlation between virtual reality and 3D printing.