PS4 & PS5, XB1 & XBS
Initially release on PC, Aspyr ported Humankind onto PS4/5 and XB1/XBS. I worked with the optimization team to ensure a smooth gameplay experierience for our Gen 8 users. In the process I deepened my understanding of Unity and XBox profiling tools for memory and CPU utilization, developed solid strategies for addressing core performance problems, and became the subject-matter expert for all things related to asset loading on that project. The initial PC release of Humankind was shipped with a major structural issue I spent most of my time wrestling with: nearly all loading was performed synchronously and the expectation of that sychronicity was woven into the fabric of nearly every feature. For Gen 8, the result included 10+ minute loading times into gameplay, hitches during that loading in excess of what's allowed for XBox and Playstation certification, and frequent hitches during gameplay sometimes lasting multiple minutes. Many of the issues I resolved related to one of these three topics. Addressing them involved a combination of the following strategies. And while each had their limitations, there was something to be learned and gained from each. strategies:
Sychronous loading dependencies were near universal in the Humankind code base, effecting everything from the AI and save system to terrain rendering and UI. Still, refactoring large swaths of the code base to run asynchronously was a very necessary measure. In many cases, the process was straightforward. Create async alternatives to Amplitude's custom loading wrapper and refactor critical callstacks to utilize callbacks and/or coroutines. The hard part came with resolving any issue downstream of the async refactor. Along the way, I delved into a variety of the various affected subsystems and used the expertise of colleagues familair with them to accelerate the process.
When working on ports, you often have limited information on what assets are used in your game, when they're used, and their intended lifecycle. In these situations, using handmade data collection and instrumentation can be incredibly helpful. On Humankind I did some custom analysis on the load screens to get a better idea of our asset loading dependencies and overall utilization. This process revealed a large amounts of time wasted on failed dependency resolution, prompting me to reorder certain load processes and kickoff certain load requests in bulk during periods of otherwise infrequent disk utilization. This process also revealed a few ways in which preloading could improve our player experience.
Analyzing the game's asset usage revealed a set of large assets used consistently through gameplay regardless of the player's progress or playstyle. These assets were migrated into an assetbundle that gets loaded by Unity's preload system, reducing our load times and minimizing memory fragmentation during extended periods of gameplay. On Gen 8, heavy fragmentation was a persistent cause of out-of-memory crashes.
