Colossal Order Ltd

Colossal Order

Game Development Studio

Hi and welcome back to another development diary for Cities: Skylines II! We’ve talked about the people living in your cities before, their wants and needs, and how they affect the simulation, but today we focus on the models themselves, our goals for them, and the process of how they came to be. 

From the very start, we had a distinct goal: we wanted a clear and definite upgrade from Cities: Skylines in all aspects. The new Photo Mode camera allows you to get pretty close, so citizens had to have a level of detail to match this. But we also wanted our citizens to have much more variation to create a more inclusive and realistic gaming world. It was essential to us that the characters in Cities: Skylines II represent a broad spectrum of humanity, including different ethnicities and body types.

Achieving this diversity required a flexible and efficient system for creating character models across all the different age groups of the game. It was clear that a tool was needed to combine all those aspects and on top of that a great variety of hair, clothes, and accessories needed to be added. Lastly, it was also a major requirement that animations should work with any type of character model regardless of the body type.

Real cities are full of diverse people and we wanted Cities: Skylines II to reflect that reality


This is where Popul8 comes into play. We partnered with Didimo, who created the Popul8 character design software that perfectly addresses our design needs: Create a lot of varied characters quickly and easily. We had our own art style for the characters and for this, Didimo created a base mesh to represent that style. With this external tool groups of citizens could easily be created for different seasons, age groups, and jobs, and then these could be imported into the game.

We had a set of early placeholder characters during development, which did not have much variety, so getting the first batch of final characters into the game was quite exciting for us. Suddenly the game came alive with a myriad of people walking the streets, doing yoga in the park, or taking selfies in front of interesting buildings. It brought in both young and old, tall and short, heavy and light citizens of all different ethnicities, bringing realism and diversity to the city. And when they started to choose their clothing according to the temperature, we took another exciting step toward more realistic citizens.

A sneak peek at how characters are created in Popul8


As we wanted a lot of variation in the game, this meant a lot of character models. The game has children, teens, adults, and seniors all of which need to be done separately and set up so that their physical appearance remains the same through all ages. Some might change their hairstyle or gain or lose some weight but in general, they are recognizable throughout their lifetime. When working on new characters, we usually create a group of 100 characters with similar setups at the same time. As an example, let’s say it’s a group of adult people during wintertime.

100 adults in winter gear in Popul8. Color variations for hair and clothing are not shown as these are set in-game.

We have several sliders which control variables for age, tall or short, thin or fat. There are also several sliders for different ethnicities to ensure the characters look just right. As this is a group of adults the age slider is set to about middle with some allowed variance. Other sliders can have full range to give the group a good variety of height, build, and ethnicity. Next, we create sets of winter boots, jackets, trousers, headgear, and accessories from which clothing is randomly picked to form the characters in Popul8. Additionally, we have several versions of hair and tattoos for even more variety.

Once the characters are generated, they are checked to avoid any combinations that look way off. Some weirdness is okay, we want characters to reflect experimenting with different styles, but occasionally some just go a little too far from reality. Once we are happy with the group, it is exported from Popul8 and then imported into the game. 

The original texture assets are usually a neutral gray to allow for even more variations of color for the clothing, hair, and accessories. Once in the game, artists choose color palettes for the characters. It’s a fine balance between too garish or too dull and we have included both common and rare color choices to represent the variations you find in real life. Some people love a splash of color while others prefer more muted tones, and our character models should represent that.

Selecting a jacket for the character
Getting your hair done


There were quite a few challenges with the character models for Cities: Skylines II. Some of these challenges were technical and expected, like what is the art style, what are the proper blend shapes, how clothes work when they are layered on top of each other, and how to compress animations. Other challenges were trickier to solve, like how different sizes of characters fit onto motorcycles or retargeting animations for children so they all look correct. Then there was just picking clothing combinations that looked realistic but interesting and not too odd – that was more of a fun challenge and it was great to see all the possibilities of the tools.

Looking to the future, we want to add more variations in character blend shapes, clothing, and pretty much all aspects of character models, so the city has a wider spectrum of citizens. This also includes animations and accessories for disabled characters and much more. While we have many ideas ourselves, we are always eager to hear from you about the kind of citizens you would like to see and which ones grow to become your favorites.

This brings us to the end of this development diary and we hope you enjoyed another peek behind the curtain. We’re back tomorrow with the last of this mini-series, where we cover the Tutorials & Advisor and how they can help you build the city of your dreams.

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