Dev Diary - Renewed Cities by Brum

Hello everyone!

Welcome to my Developer Diary about the Content Creator Pack: Renewed Cities for Cities: Skylines.

First of all, let me introduce myself: I’m Brum, a Brazilian architect and designer passionate about architecture, urbanism, and a big fan of Cities: Skylines. 

Living in a tropical country, I’ve always loved assets that represent my place and culture. But, there weren’t as many of them on the Workshop as I’d like. That’s why, at the end of 2022, I started learning 3D modeling and began creating Brazilian historical buildings and contemporary assets from tropical countries.

Some assets from my Workshop, which I opened in 2022.

However, Renewed Cities goes beyond. I wanted to bring something that would connect with players from all around the world. It’s a pack inspired by cities that have found bold ways to renew their urban centers without erasing their history. By blending the old and the new, these cities have transformed urban life and created extraordinary landmarks.

All assets in Renewed Cities embody this contrast between old and new, with steel, glass, and concrete structures emerging from traditional buildings. While the historic parts connect seamlessly with nearby classic architecture, the contemporary additions introduce unexpected elements that will reshape your city’s skyline.

Initial mood board for Renewed Cities, featuring inspirations from Toronto, Rio de Janeiro, Buenos Aires, NYC, Hamburg, Lyon, Antwerp, and more.

To define which assets would be created and what their style would be, my research was guided by two key aspects: Function and Form.

Urban planners are always looking for ways to attract major companies and new residents to revitalize downtown areas. In addition, cultural, educational, sports, leisure, innovation, and creative economy spaces, along with social housing and parks, are key components of such renewal projects.

Contemporary urbanism, which aims to bring all these functions close together to create vibrant, livable cities, inspired my decision to design a CCP featuring a wide range of functions: office buildings, residential buildings, unique buildings, service buildings, and parks.

After defining my list of assets, I conducted extensive research on architectural styles. I compiled a panel with around 800 visual references from across the world that I might want to add to my pack.

At the end, I arrived at this long list, outlining the main design guidelines for the project.

For each asset, I created a moodboard with three final references. In the next phase - modeling - I’ll try merging these ideas to see whether the envisioned concept will result in cool assets.

Based on the moodboard, I built a simple volumetric model for each asset, studying their scale within the city, approximate footprint, and height. After placing them together, I adjusted some proportions to bring greater impact and diversity to the overall set.

Basic volumetry of the proposed assets.

With the basic volumes and moodboards defined, I began the detailed modeling of each asset. The main challenge from this point on was to produce a significant number of assets and landmarks within a limited timeframe. In the case of Renewed Cities, each asset was essentially two - one historic and one contemporary - fused together. The first step, therefore, was to systematize the workflow. 

The first 10 modeled assets.

For the historical part, I created modular pieces that could be assembled to form buildings quite different from one another. I also included special elements such as domes, pediments, and porticos, which are essential for distinguishing and personalizing each building.

The Flagship Store and the University share some of the same façade elements.

For the contemporary parts of the assets, however, I worked in a more free way due to their geometric diversity and complexity. Each one should look as if it were designed by a different architect, with their own distinctive style.

Museum, Sports Center, Library, and University are four of the most complex models in this CCP.

In modeling, the triangle count is crucial to ensure good in-game performance. Basically, you need to decide which volumes will be physically modeled and which will be represented through textures only. If a good number of volumes can be made by textures, then you achieve a reasonable tris optimization. In Renewed Cities, almost all assets range between 15K and 20K tris.

The historic façade of the University has few tris. Many decorative details are created with textures only.

When creating building assets, I consider texturing to be the longest and most challenging stage - it requires patience and close attention to detail.

Renewed Cities features a wide variety of architectural styles, which translates into a large number of textures. The historical architecture includes four distinct styles with many façade details. The contemporary part, in turn, showcases a multitude of materials and construction techniques that give each landmark its own character.

The assets in this CCP are not replicas, so there was plenty of room for texture experimentation. One of the initial concepts was to create buildings where form and materiality reflect their function. For example, the Elementary School was designed like a building-block toy, featuring vibrant colors. The Innovation Hub has a high-tech shape and textures. The Police Headquarters presents an austere architecture that conveys solidity through exposed concrete. And the Lofts Skyscraper, with its sinuous outline and large balconies, clearly represents a sleek, modern luxury condominium.

The Elementary School, the Innovation Hub, the Police HQ, and the Lofts Skyscraper in Blender.

To produce the textures, I primarily used Photoshop and AI tools. The AI-generated images were later refined and edited manually in Photoshop - after all, nothing replaces human sensitivity.

Example of the six texture maps for the Police HQ in the picture above. At the top, the diffuse texture (_d) is edited in Photoshop and tested multiple times on the 3D model. Later, it is also tested in the game editor, along with the other texture maps: alpha (_a), color (_c), illumination (_i), normal (_n), and specular (_s).

Importing the mesh and textures into the Cities: Skylines editor allows previewing the asset in-game, across all variations — map types, snow, day, and night. But that doesn’t mean the process is finished. Based on what the editor shows, textures are further refined in Photoshop and re-imported into the game as many times as necessary to achieve a perfect balance of color saturation, reflections, and nighttime lighting.

A set of assets viewed in the late afternoon, when the first city lights begin to turn on.

Only when the textures are 100% finalized do I begin adding decorative elements. These bring life and richness of detail to the assets. Renewed Cities feature many open-air leisure spaces, such as parks and large terraces, so these elements play a key role in defining the atmosphere.

Fortunately, the game includes a wide variety of vanilla decorations, which make it possible to create anything from refined nighttime lighting to beautiful landscaping projects. To complement them, this CCP also includes a set of contemporary design props related to outdoor living - café tables, chairs, lounge chairs, tents, bar, and more.

Sports Center terrace with various props from CCP Renewed Cities.

When it comes to parks, Renewed Cities offers a variety of sizes to fit different lots, ranging from 2x2 tiles to 8x16 tiles. The three largest parks can even be combined to form a large Central Park-style complex measuring 24x16 tiles. The pack also provides standalone decorative elements, allowing you to use in-game tools to design your own custom parks on an even larger scale.

View of the three 8x16 parks, forming a large central park.

With the assets finished, it’s time to create the LODs. As many players know, an LOD (Level of Detail) is a simplified version of the asset with a reduced tris count and texture size - like a miniature model that replaces the main one when the camera zooms out, helping optimize the game’s performance.

The greatest challenge in creating a good LOD is to avoid a noticeable transition during zoom in and zoom out, when the full model switches to the simplified one. Some LODs had to be reworked multiple times to make this transition smooth and almost imperceptible.

Comparison of the main mesh (left) with the LOD (right). While one should look perfect at the largest zoom-ins, the other should be as simple as possible.

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To conclude this Developer Diary, I've included below some screenshots of the Tempered Vanilla Theme at different times of day and night, without using color correction mods.

I’d like to express my gratitude for the privilege and creative freedom I was given to bring Renewed Cities to life. I’m excited to see what Cities: Skylines players’ imagination will create with these new assets. Thank you very much!

Daniel Brum

Follow Brum here

Cities: Skylines 1 Workshop: https://steamcommunity.com/id/DBrum/myworkshopfiles/

Cities: Skylines II Paradox Mods: https://mods.paradoxplaza.com/authors/DBrum

Instagram: https://www.instagram.com/dbrum23