In the last instalment of this blog series, we created a rendering pipeline to allow for drawing multiple objects according to their priority, and we also created a GUI anchoring system allowing us to create dynamic and scalable GUI elements.<p>This time around, I wanted to work on something a bit more interesting: Collisions. Now this took much more time than anticipated. What started as a simple collision detection and resolution system quickly escalated to a full-blown scientific paper comparing five different collision systems. In this blog, I will give an overview of three methods implemented with "pure" ECS as well as share some of the results from the paper I wrote.