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Behind the Scenes #5: Citizen Characters

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.

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


POPUL8
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.

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A sneak peek at how characters are created in Popul8


GROUP OF CHARACTERS
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.

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

HOW IT’S DONE
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.

INGAME SETTINGS
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.

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Selecting a jacket for the character

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Getting your hair done


CHALLENGES
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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I agree. This might be the cause of the performance problems. Since it has ties to the population numbers (bigger city = more citizen models). At least lower the tris in the meshes and if you can, get some LODs (or increase them if they have them already) added to them.

I understand that you’re possibly trying to make this your “SimCity” for your “Sims” (Life by You). at least try to get these models more optimized.
 
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How can a game look so bad in so many aspects and at the same time be so GPU intensive?

I can see two things went wrong. First, Unity’s engine is garbage! And second, the developers are not good enough for this. They should have hired better developers, not mediocre ones.
 
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I'm sorry but these models are just plain terrible. Everything I've seen so far through content creators and through this very diary does not seem worth the likely performance hit these models are causing.

The animations are robotic and seem low quality. Body rigs are not well proportioned, resulting in strangely lanky characters or more overweight characters having thin arms. They have these strange, creepy expressions and so many have huge heads. The hairstyles are off and not well put together, at times it's a flat texture and at other times they have wooly hair which looks more like strings from a mop. They have a weird relationship with lighting in general. Clothing seems too limited and doesn't mix well together.

It's just weird that so much effort was put into making the citizens look as highly detailed as possible even though we spend most of our time high above the skies, meanwhile terrible concrete and grass textures are layered on the assets that we're going to be looking at for most of the game while they also lack clutter and detail... It's also weird that this is considered an upgrade graphically over the cims from CS1 which IMO did their job very well without needing all of this complexity.

I'd say that this is a good example that sometimes the simpler solution is better than a highly complex one. The faceless low-poly models from CS1 look better than these high-poly randomly generated models. I think the modelling team should really rethink their objectives and methods from the ground up, because something is clearly missing in this game stylistically even though it demands so much more than CS1. The foundations are there, the engine is clearly capable of making good looking stuff, but I feel it just wasn't planned for or executed right, resulting in grey, lifeless cities populated by strange humanoids.
 
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Now I think of it, this might actually be a good thing. Let's say you want to create a Japanese themed city you want to add way more Asian looking citizens to the city, so you'll only check looks suited with your city-vision.

All of this should have been incorporated in base game though, I honestly thought they would at least do something depending on where we choose our broad location.
 
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I think this is the cause of the performance issues. They use Popul8, which is no problem at all in the end I think. But the models are clearly not optimized yet. And if you render underwear and teeth / gum for each cim, then you will get a performance problem, because at 100k citiziens, and yes, probably not rendered all at once, but still, you will see high-end hardware struggle.

Calculate 19k tri's times let's say 25k .. the card has to render 425 millions tris already. For the CIMS alone. Your high-end card will have trouble rendering 25 million tri's already.

But for me, this is hopeful! I think a lot of optimization will be done on the CIMS, lower polycount drastically, more LOD's.
 
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These cims have glaringly obvious issues visible to a layman like me, and you’re going to tell me not one person at CO or PDX ever stopped to question these? These are acceptable quality for a sequel to a game that sold 12 million copies and expects another $50-90?

Tongues, underwear, teeth. These things are wasteful and it’s absolutely appalling that they were not optimized out.

It seems these were procedurally generated and not touched afterwards. If I submitted work to my boss next week using AI or Proc Gen with no human input, I would be quickly out of a job. Indefensible.

With all of that out of the way. The placeholder cims would have worked just fine, in fact, I think they are more attractive models as well. I am not sure why they were discarded for these.
 
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Never seen a thread on here with so many responses I agree with.

I assume these detailed characters and the animation challenges referred to are a factor in why there's no bikes in the game?

I mainly wonder, did any players actually ask for detailed character models? eyebrow variations, buttons on jackets, selfie animations (ugh) instead of fences, benches, more train stations, etc.

This feels like very skewed priorities and something that could have been added as an update later when the simulation was stable or a DLC with customisation options for those intersted.
 
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I assume these detailed characters and the animation challenges referred to are a factor in why there's no bikes in the game?
Doubtful, bikes likely were dropped earlier, during development of the simulation. Remember that motorbikes still exist. I doubt that the animations were considered at that point.

I mainly wonder, did any players actually ask for detailed character models? eyebrow variations, buttons on jackets, selfie animations (ugh) instead of fences, benches, more train stations, etc.
It could be that some people who like to visit their cities in first person asked for more details. Though I can hardly imagine that this fidelity was asked for. The models are extremely detailed for background fluff.

This feels like very skewed priorities and something that could have been added as an update later when the simulation was stable or a DLC with customisation options for those intersted.
I suspect that this actually was part of the thought process for using this tool to generate the cims. Get a working tool, refine later. Or they had to scrap their previous approach.
Keep in mind that some quirks of CS1 probably were a priority to get removed, like the people waiting on train stations sorting themselves by color.

The good news is that, if the highly details cims are a noticeable part of the reasons for the bad performance, then optimization has quite a bit of easily fulfilled potential.
 
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A lot of people are saying they don't have LODS, this is incorrect, when fully zoomed out they just disappear, when you are looking over the street from lets say roof height they are very low poly and only become full high poly when you are close enough on street level.

I guess they are now 20-40k tri's each, which is almost just as much as The Sims 4 (those are 30-50k). These could actually be the meshes for Life By You. I think 10k should work just as fine, CS1 citizens were only 1-2k if I remember correctly, so that's still 5x more detail than before.
 
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Also under "challenges" - keeping bras on the inside!

Jokes aside, assuming (and of course they may not!) these upgraded sims have any significant performance impact it would be nice if we could have an option to remove them from the game. It seems to me like almost all the time they add nothing given how zoomed out we are.
 

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Well that explains how these character models came to be, I was wondering why anyone would chose models of this detail level for a city game.

Would it be worth disabling the highest level of detail on these character models for now ? Just to improve performance.
 
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I have no objection to people be able to use these very detailed models if they want to take detailed photos on very expensive hardware.

But I think many (most?) of us would be happy with the 'placeholder' Cims so we can build bigger cities on affordable components.
 
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I'll say that these details don't necessitate these higher-poly models. I like that citizens can change clothes depending on their job and season, have random accessories, and can gain and lose weight, and lower-poly models would be enough to express all that.

As a citizen asset creator, I would like to create a set lower-poly cims that can express all of these details.
 
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I do like that the cims appear substantially improved from the earlier builds... those earlier cims looks chonked & like they were moseying on up to a duel in the Old West. It seems like those criticisms are being improved upon, which is great to see. Personally I like being able to have this detail when I'm down at ground level...

...but agree with many of the comments that that's not where I spend the lion's share of my time, and am wondering how/if this affects the game. There's a risk of improving things so much that you now find yourself too far in the opposite direction (and perhaps at the cost of resources that could've been put into further developing other parts of the game)...
  • Performance Impacts - How performance-heavy are these models? Can we turn them down to humanesque blobs if we want to boost performance? Or will the game take a page from the Total War games, adjusting the levels of detail depending on how zoomed in you are, or if perhaps upscaling if you're in cinematic mode?
  • Future-Proofing - How future-proofed will these models be? If future updates or mods add in bicycling, skateboarding, rollerblading/skating, etc... will these models be able to readily adapt to those new uses? Or if updates/modders add in additional life progressions (such as young adult) how can these adapt?
  • Editor & Assets - I think I'm reading this as saying that we'll have access to editor tools for both characters, hair, clothing, etc? Right now that image of 100 winter-clad adults shows a lot of repeating hairstyles & jackets... will we be able to create or download more hairstyles, clothes, etc?
  • Emotes & Movements - Do cims have accompanying emotes and movements, and are those definable at all? Like maybe we want a culture where people tend more toward covering their mouths when they laugh, versus an uncovered bellowing laugh. Or maybe we want some variation in fast-walkers versus those who casually take their time.
  • Environmental Effects - Can the built environment affect things? Like if we have a lot of active recreation: people might walk faster. Or if we have a booming textiles industry: people might dress with flashier colors or more expensive clothes?
  • DNA Sharing - I'm a bit confused over the "Ingame Settings" section, which seems to be for creating individual cims? Which if so, that's definitely a feature I'd look forward to. Can we save individual characters DNA (a la CK3) and share those? That could be fun for putting friends into each others' games, or for streamers to put their viewers into games.
  • In-Game Settings - Do we have any control over how cims appear at large? Does the game just give a general melting pot of everyone, skewed slightly toward bland fashion? Or are there presets like "Generic Western", "Generic East Asia", etc? /// Or can we really dive in to define ranges & variability for things so that we could have a punk caricature of Berlin full of mohawks and black leather, or recreate Miami with colorful swimsuits & collared beach shirts, or a DC-esque city overwhelmingly consisting of suits, or an immitation Lagos with white business attire mixed with colorful dashiki & dresses, or or a Tokyo-inspired mix of salaryfolk & highly eclectic hairstyles & fashions?
  • Conditions - Do conditions affecting cims have any impact on their appearance, such as if they're sick or homeless? Are there hairstyles, clothing, other assets, emotes, movement styles, etc. that can vary depending on conditions?
  • Work Clothes - Are there clothes defined for different jobs, and the people working those jobs will dress accordingly? Imagining suits or office casual for office workers, more casual-casual for retail, blue collar for industry, varying uniforms for gov services, etc. Or will each cim have a "work clothes" palette that might not reflect what their job actually is, and we'll have people in suits fighting fires or working factory floors?
  • Kids - Are kids totally randomly generated, or do they pull traits from each parent?
  • Actors - (per a previous Dev Diary) In Cinematic Mode can we direct a specific person to do a specific thing? Like they'll sit on a bench in a park, or turn the corner and bump into friends, or an action sequence of someone running toward a roof's ledge with police in pursuit, etc.
  • Individual Preferences - (per a previous Dev Diary) I've seen a few references to individual citizens' preferences. How will these work? Are they stamps like "Industrious" or "Lazy" that someone might have, or does every person have some variability across multiple factors... like maybe everyone has some 0-to-100 score on "Work Ethic" and "Education Desire" and "Luxury Preferences", etc? (I'd love if we could have highly digital seniors that still dive into electronics purchases, or luddites perfectly happy without internet & perhaps even without power) And how are these preferences assigned... are they random, or inherited from parents, or affected by environment, or a mixture of these?

Thanks!!
 
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