Create 3DCM with Blender

October 18, 2023

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Three Dimensional City Model (3DCM) is a 3D model based on 2D geographic information. Blender is a free and open-source 3D computer graphics software toolset for creating 3D-printed models, motion graphics, interactive 3D applications, virtual reality, and even the Metaverse.

Data Sources

The data source is from Blender-OSM plug-in, which downloads from OpenStreetMap. Open the Blender software, click the plug-in bar in [Edit] -> [Preferences], and install the installation package downloaded from Blender-OSM.

Click here to download Blender-OSM

After the installation is complete, find the plug-in, open the drop-down settings, first select the save location of the map data on the local disk, then register on the MapBox and add AccessToken under the account information, copy and paste it into the MapBox access to text box of the plug-in.

Data Preprocessing

After the data source setting is completed, click the N key on the keyboard to find the osm plug-in, select the terrain, and select range to jump to the map page, where can freely choose the research area we need.

After the frame selection was completed, went back to Blender and pasted the scope of the selected area. Click Import, waiting for the terrain data of the research area to be downloaded.

Download the satellite image map on the ground and choose image overlay . As we use Mapbox's token in the plugin settings, so select Mapbox Satellite in the overlay column, and click Import to wait for the download to complete.

Model Establishment

Select image buildings to download 3DCM and load the city building data.

Select the building model in the scene, press the tab to enter the edit mode, click select, then press the Y and P to separate the roof, and press the tab to exit the edit mode.

Add Texture

Open the shader editor in a new window, click the roof material node, select the BSDF, press and hold CTRL+T on the keyboard, add the downloaded satellite image), then create a new window, open the UV editor, and press the small button on the 3D view interface. Press keypad 7 to enter the top view angle and TAB to enter the edit mode, press the A to select all the building roofs, press the U to select the projection from the perspective, and use the S and G keys to adjust the position of the satellite map until it is aligned with the base map.

The same method is used to map the surface of the wall, add an image texture in the shader editor, import the architectural texture downloaded from the Internet. Then Adjust the size of the rectangle through UV projection - Block Projection to make the texture fit more entirely to the building wall.

Summary

With the continuous development of GIS technology, 3D GIS has become one of the development directions of the current industry. The powerful functions and uses of 3D GIS are not only to provide data for the development of digital cities but also to be used in urban analysis applications, such as in urban planning, architectural Construction, public safety management, urban emergency command, community service, and medical care all play a very important role.

Create 3DCM with Blender