Cities Skylines II enables the creation and import of a diverse range of assets. This guide aims to provide details for each asset type and will be further developed.
The basics
Meshes and textures
Cities Skylines II uses a variation of the standard PBR pipeline (with metallic/glossiness), but there’s some additions involved to cover the game’s special needs. Information about different texture channels can be found from the list below. To create an asset you need to produce the following for import into the game:
- .fbx meshes, 2018 version - UV mapped
- .png files, Texture Sets
- BaseColor
- ControlMask
- MaskMap
- Normal
- Emissive
Each texture should be named as a suffix to the name of the mesh it is used. For example:
- ExampleMesh.fbx
- ExampleMesh_BaseColor.png
- ExampleMesh_ControlMask.png
- ExampleMesh_MaskMap.png
- ExampleMesh_Normal.png
- ExampleMesh_Emissive.png
Depending on what software you use, you can create your own textures with the following channel structure.
| Texture Set | Channel | Channel Name | Description |
|---|---|---|---|
| BaseColor | RGB | BaseColor Diffuse Map | The basic diffuse map for your mesh. |
| Alpha | Opacity | Defines which parts of the texture are alpha clipped. White is fully visible and Black is transparent. The alpha clip threshold is at 50% Black. It either renders as opaque or fully transparent. | |
| ControlMask | R | Color mask 1 | Color masks come in sets of 3 and are used together. Each color mask should be mapped mutually exclusive to other color masks. Black through to White applies the selected colors to the diffuse map using multiply blending. Black is no color, and White is full color. |
| G | Color mask 2 | ||
| B | Color mask 3 | ||
| Alpha | Snow Remove | Specifies on the mesh where automatically generated snow is removed. White is no snow, Black is full snow. | |
| MaskMap | R | Metallic | Defines how metallic the diffuse renders in game. White is full metallic, Black is not metallic at all. |
| G | Coat | Applies an extra shine, or glossy coat to the diffuse on top of the standard glossiness. White is full coat, Black is no coat. | |
| B | Default Black | This channel is not currently used and should remain Black. | |
| Alpha | Glossiness | Defines the glossiness of the diffuse. White is very glossy, Black is not glossy at all. In the standard PBR workflow, glossiness is the inverse of roughness. | |
| Normal | RGB | Normal Map | Your normal map uses OpenGL. Normal maps are used to visually add depth to the diffuse textures. |
| Emissive | Greyscale | Emissive Map | Applies an emissive effect to diffuse, White is full bright emissive and Black is no emissive. |
General notes
- Meshes can be modeled centered on the origin as the editor provides tools to move or rotate the mesh, enabling you to position it manually.
- Scale is 1:1 except when assets are enormous and need to be scaled down from their real-world counterparts to fit comfortably in game. The 1:1 scale is kept for the vertical axis to maintain the correct size compared to the characters
- Triangle count limit is also not specified, as it depends on the size and complexity of the asset you are modeling. For example: zoned assets in the base game range from 3000 triangles to 95000 triangles and they fit inside a 6x6 cell maximum lot size. Some of the unique service buildings that are much bigger than the zoning limit of 6x6 cells have over 100 000 triangles.
When optimizing your triangle count, try considering the lot size, how tall and how complex the building is, and be conservative with your modeling.
- Texel Density isn't specified for assets. When UV mapping you should aim to have a similar texel density for every UV island, however you can try to balance by giving the larger, more noticeable features of the asset (like the roof and walls) a higher density than the smaller features (like window frames, door handles etc).
- Minimum texture sizes are outlined per asset category. To define the high quality texture standards for Cities Skylines II we recommend that these specifications are rarely exceeded, if at all.
Asset categories
Buildings
Coming Soon
Props
Coming Soon