GCAP 2017

Visibility queries, i.e. quickly finding the smallest possible set of geometry required to render a given scene, are a feature of almost all game engines. They are almost always on the critical path for performance since they need simulation to be complete, and prevent rendering from starting until the results of the query are available. This makes efficient visibility data and code very important to overall game performance.

This is an experience-based talk, so I'll be going into real problems that we faced and solutions we came up with for rendering the world of Horizon Zero Dawn. I will describe the issues we faced in moving from the relatively constrained environments of the Killzone series to the open-world vista of Horizon, and how they affected our visibility system in particular.

I'll talk about where we came from, the goals for visibility in our new world, and the system we built to fulfil these goals. I'll go into our visibility data in detail and talk about how we take advantage of the PS4's asynchronous compute capabilities to query the millions of objects and quickly produce results for the renderer to consume.

I will sum up by talking about lessons we learned in shipping the game on the current visibility system, and where we're planning to take it next.

I'll explain things as I go along, but a basic familiarity with GPU compute will be helpful to get the most out of this talk.