UNITY landfills and engine caused the low performance of CITIES: SkyLines 2

Paradox Interactive, together with developers from the Colossal Order studio, launched a large -scale urban planning simulator CITIES: SkyLines 2 on a PC. A game where the main gameplay is to manage resources and effective city management has distinguished itself with extremely weak optimization. The performance of CITIES: SkyLines 2 remains unsatisfactory even on top video cards, so players have to install the lowest chart settings. While Colossal Order is preparing patches to improve optimization, enthusiasts managed to find out the reason for low performance.

According to the detailed technical analysis of CITIES: SkyLines 2 from Paavo Huhtala, the main source of the problem is the training grounds and the engine of the game Unity. Analysis of the game rendering showed that the project generates a huge number of landfills, most of which simply do not make sense. In addition, the project does not provide a dynamic system for reducing landfills if necessary.

Cyberpunk 2077 also uses a large number of landfills, the number of which for one model can reach 29,500. But this make up triangles that build common corners and are sewn together, forming the tops of the landfills. The real number of such vertices for clothing in Cyberpunk 2077 is only 8,000, while Cits: SkyLines 2 uses 25,000 peaks.

In the CITIES: SkyLines 2 engine in one frame there are about 7000 rendering calls and more than 50,000 API calls (requests performed by playing through DirectX). By themselves, without context, these numbers mean little, but in general they create a huge load on GPU. And this is already to blame for the Unity engine itself, which is used for rendering.

The author of the technical analysis suggests that the developers had to write a lot of additional code to use HDRP rendering technology. This type of rendering at the time of development of CITies: SkyLines 2 has not yet been fully implemented in Unity, hence excessive loads on the video card.