GoThrough: a Tool for Creating and Visualizing Impossible 3D Worlds Using Portals

Portals are commonly used in video games (e.g., games like Portal, Antichamber, and the classic Asteroids). In this work we introduce GoThrough, a tool that enables users with little to no previous knowledge to add transformative portals to 3D scenes in the Unity game engine. We map the existing literature in portals, both in terms of academic works and web resources, as well as entertainment usages. Then, we introduce an approach for portals to work robustly both in terms of geometry and rendering, and explore common pitfalls (as well as how to handle them). The tool is shown to work in a variety of example scenarios, and has been evaluated quantitatively for performance, providing real-time performance in a variety of scenarios. User tests have also been conducted in order to analyse GoThrough qualitatively. With a SUS score of 87.5, we concluded that GoThrough is intuitive enough to be used by non-experts, making the process of creating impossible 3D worlds much less cumbersome.