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Greetings everyone,

Today, let's have a look at the two biggest changes/new stuff happening on the Modding side of Cities: Skylines.
Let's get started on how the day/night cycle affects the Asset editor and user-created models:
After we decided to add this feature alongside the After Dark expansion, our first reaction was to ponder what would that mean for the ton of assets already created on the Steam Workshop. We knew it would be impossible to completely automate the process to lit those assets during night time, but we wanted to minimize and ease the amount of manual work required by content creators.
Our first step was to turn all prop assets which are expected to emit light into assets emitting light. Street lamps/poles (see below) and so forth are heavily used in custom assets, therefore it made sense to take that road, as it would provide a base lighting for all assets already using them.

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To allow more granularity to the lighting process of a building, we also added various light props such as wall-mounted and floors lights. Heck we even added a sub-category to the Common Props toolbar. Below is an example of how to properly mess up the night look of a residential building using wall-mounted lights, also features the new Light props toolbar.

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In order to visualize the asset both at day and night time in the Asset Editor, we replaced the previously existing slider Light rotation to control the time of the day. The lights toggling/animation logic are simulated in Editor just as they would be in-game, so the preview of the building for a given day time is accurate.

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The dynamic lighting was the first aspect to consider, but we also needed a way to get the windows to lit up therefore we added support for texture-based illumination using illumination maps.
Conveniently, we have had illumination maps all along (the _i suffixed images used when importing asset) but they have obviously been heavily underused as our themes only features day time until now.
It used to be the illumination map acts as a mask where a value of 0 (black) means no illumination and a value of 255 (white) means full illumination using the diffuse texture information.
We preserved this behaviour but squeezed the color value to range between 0 and 120 instead, where 0 still mean no illumination contribution from the diffuse texture and 120 means full contribution. We hereby freed the range 128 to 255 to allow windows to be lit randomly. A value of 192 means neutral, so if you want a building to be unlit at all times, the illumination map needs to be solid 192. The likelihood of a window to be lit at a given time and its intensity are randomized for values within 128 and 255, the closer the value is to a boundary the more likely it is to be lit and stronger.

As an example below is a residential house with its windows lit and diffuse, specular and illumination map composited next to each other.

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In this case, the UV mapping is such that the windows use very little texture space but you can see them clearly at the bottom right of each texture. Notice the illumination map value of unlit areas is 192.
Also, the specular map, while irrelevant to the lighting is shown in the picture as it is worth noticing in most cases, if you have already created a specular map for your asset, you already have a base windows mask to derive from when creating the illumination since windows are usually reflective and you have already cranked up the specular mask color.


Next, let's talk about a brand new feature which affects both content creators and players: District styles.
After shipping the free patch introducing the European theme and buildings, a rather high demand for these buildings to be made available in all themes rose from the forums. It was not done as such because of both technical and visual motives:
- memory usage would have gotten very tight for our user with minimum system requirements and we did not want to break the game for them.
- Buildings have specific requirements to tie-in with corner buildings and we would have needed to redo the entire stock buildings set to scale with the wall-to-wall and corner buildings feature. That obviously was not a viable option.
Coincidentally, another pretty highly requested visual feature was the ability to set a policy which would define the look of a district.
While we did not feel comfortable making this feature a policy as policies should have an impact on gameplay and not purely on visuals, we did add an option to select what we call "Styles" from a new Dropdown component in the District info panel.
We added a default building set with the European buildings and when enabled in the Content Manager, it will be available in the game dropdown.

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Once a style is set to a building, it will start using/replacing buildings from that style matching the level and density requirements for spawning hereby you can have a European style district in your city.
The screenshot below shows European buildings in the good old Los Santos map which is built on a tropical theme.

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This is pretty cool but here is the good(er) news: content creators can also create and share their own styles on the Steam workshop.
In the Content Manager, there is a new section called Styles and you can create a style to which you can add any building uploaded to the Steam Workshop.

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Provided you include buildings which covers all levels and densities used in the game, you will have a fully customized look for a given district \o/
We can't wait to see what new amazing combinations you are going to come up with!

That's it for today.
Thanks for your time reading this diary, it's back to coding for me, there is still some work to be done :)

/damsku
Technical Director @ Colossal Order
 
I would suggest that we disable the cloning feature in our mod (only remove the option to create new clones in the theme manager) and warn users with clones in their themes that the feature will not be supported by the official theme system.

Entirely reasonable.

Make the Theme Manager GUI work with the official theme system (ingame creation of themes with 3d preview = awesome)

Great! I'd like that.

Create a mod that allows you to select multiple themes per district (if possible)

Absolutely crucial! I can't imagine going back to only one theme/style. Most of my districts are a mix of two or more themes, and that's the way I want them to be.

splitting and merging on update

This is my only point of contention. I want my lots the way I laid them out (which I most likely did manually). If there's no higher level building for that lot size, then so be it. House remains. (Unless you make it an optional feature, then I'm all for it.)

Everything else looks good :)
 
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The illumination maps are different than the specular maps so no worries there. The illumination map function been in the game all along. Those end with "_i" So you don't have to touch the spec maps at all. What you can do to save time is do a "save_as" with your spec maps putting _i instead of _s and tweak from there.

Yes I understand that part, but my point is we have to add/update an illumination map, so we have to re-import all our assets with an extra texture, decorate them again with props, override our previous save files and update them all in the workshop. I got quite a few houses who need to be updated then..
 
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The District styles goes hand in hand with the modding additions (creation of custom styles) which we really want available to everybody. So the feature will be available in the base game, it will just arrive at the same time than the expansion.
However, there are plenty of other cool stuff which comes with the expansion only, so you should still buy it ! ;))

If it's game-wide, then what's changed performance wise that you can have this feature without negatively impacting performance as it was one of two reasons to not have this feature before.
 
This is my only point of contention. I want my lots the way I laid them out (which I most likely did manually). If there's no higher level building for that lot size, then so be it. House remains. (Unless you make it an optional feature, then I'm all for it.)
Well, if we create such a mod, we will add a few options in the settings menu to enable and disable features.

For manually laid out building, I would recommend you the "Control Building Levelup" mod which allows you to lock levelling for every building individually (or per district). It is a very nicely coded mod, better than "hacking" the themes.
 
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so we have to re-import all our assets with an extra texture, decorate them again with props, override our previous save files and update them all in the workshop. I got quite a few houses who need to be updated then..

I was told you don't need to redecorate them, you can choose to select use pre existing props as the template and it will import the model with all the props in place as they were before. I never tried it, but I'm told you can.
 
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The District styles goes hand in hand with the modding additions (creation of custom styles) which we really want available to everybody. So the feature will be available in the base game, it will just arrive at the same time than the expansion.
However, there are plenty of other cool stuff which comes with the expansion only, so you should still buy it ! ;))

Will a new style be included? Perhaps mediterranean? Pretty please?
 
I cannot wait to shut off my power stations to see how dark it gets!
 
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I cannot wait to shut off my power stations to see how dark it gets!

Oh yea that would be cool if they coded that in so if there wasn't enough power to certain buildings that the illumination mask wouldn't work and the buildings would just be dark.
 
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Oh yea that would be cool if they coded that in so if there wasn't enough power to certain buildings that the illumination mask wouldn't work and the buildings would just be dark.
I didn't even think about this. This is a must for realism. It would look silly if there was no power yet everything was still lit up.
 
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Are you guys releasing the asset editor update at the same time as the patch?

It would be great to have the asset editor features before the patch drops so we can all learn how it works and get assets updated. Or else many people are going to have very dark cities for a while after the release... ;(

Would it also be possible to tweak the street lights to have a more exponential like falloff? Light sources like car headlights or streetlight globes should render out as full 255 brightness. The light diffuses in the air, your eyeball, and camera lens, and you see these little balls of bright light that are bigger than the light source. This is why you can see streetlights for miles away at night.

The windows should be magnitudes dimmer then the car and street lights. No one lights their rooms with street lights or car headlights. I know the game isn't meant to be realistic, but it might help to make things look roughly how the human eye would see things at night.

The lights are mixing together too much and adding together, and it just looks too bright and even. Are you guys using any kind of cone or spotlight to limit where the light can shine, or is it just a point light radiating in all directions?
 
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I guess you didn't get an answer yet:

If you don't include all levels, What Happens when the game wants to increase level

Does the building Remain at the highest level that's available, does it disappear to an empty lot or does it generate an error because it can't level up.

I was just thinking, if you had a style called "Slum" and only run down Level 1 and Level 2 buildings would this be a way of creating a Slum District? Or am I misunderstanding.

The district style will only replace the service + level combinations you put in, so you can e.g. only override level 3 residential high if you wish.

If a building tries to upgrade and doesn't find a same-sized higher level version of itself, it will just not upgrade. So you can work around the system to create a slum style by inserting various level 1 buildings and then a single level 2 placeholder building that does not match the size of any level 1 building in your style.
 
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The district style will only replace the service + level combinations you put in, so you can e.g. only override level 3 residential high if you wish.
Good! Couple more questions:
What about parks/landmarks - will European parks and landmarks be available for non-Euro maps and vise versa?
Will it be possible to have a mix of services styles in a styled distict? Ex: I want to have an International police station in otherwise European district.
Also, I don't see International style in Content Manager screenshot. Will it become stock for all biomes?

Will aircraft warning lights props be present? They are one of the things that make skylines attractive at night :)
 
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(the 8 shades between 120-128 are just a safety gap and are not used)

If this is the case, is there any way to make one of these numbers cause a slow fading blink of some sort for red lights on top of skyscrapers? Also to make it consider the diffuse color so it we could make any color fading light. Here's the suggestion I made the other day based on what some people in reddit said. Hopefully you can add this function before release. :)

https://forum.paradoxplaza.com/foru...linking-red-lights-for-tall-buildings.878159/
 
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@Shroomblaze I've just asked that question :) IMO, it's better be implemented as a light prop. They add new light props anyway.

Yes a light prop would be cool specifically for the red lights, but I also think having a fading option on the illumination map would be good as well to do more than just a small red light. I'm just thinking about the possibility for the future to do interesting things with it. Plus sometimes a prop can't go certain places that you might want it to. Also it opens the door for people to make custom light models too. For Example, Light house could have a white fading light.
 
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About the District Styles, it would be very important for the player to be able to choose at least two district styles, as it is that a lot of people like to mix'n'match both default and euro buildings in districts. I know there is a mod (building themes) and the way CO seems to implement district styles is two steps backwards of what the building themes mod enables.
 
Hey, very nice update and expansion, but what about the Content Manager?

There are lots and LOTS of items in the workshop. I'm not a mod-heavy player and I have hundreds of downloaded items regardless. The Content Manager *still* doesn't provide any reasonable way to deal with many items at once, not even a simple switch to disable all the custom content! The manager also tends to get really laggy when the item count increases above just a few dozen, and it doesn't help with having to scroll through a long list to make sure that every asset is enabled/disabled according to our needs. And with every update of a workshop item, its on/off state is reset, because the game sees it as a completely new asset.

I already discussed these issues in this topic, but I guess noone noticed. I suggested things like ID-based content management, a setting if newly downloaded assets should be enabled by default, "enable/disable all content" switch (along with switches for each category), a search box to quickly find any new or specifically named assets or those from a specific author or category, and the ability to organize content into folders or groups. Those things aren't anything difficult to code, and would make the lifes of us - players and content creators alike - a whole lot easier.

Thanks in advance for considering the above.
 
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