## 2 Materials and Methods
### Data Sources
#### 2.4.1 Review of Map Providers  
In the field of interactive geospatial applications, selecting an appropriate map provider is crucial. This is because the available SDKs and libraries consist of different capabilities and cater to different requirements. Providers offer a range of services, including the provision of a high-precision WGS4 globe (a global coordinate reference system that defines the Earth's shape and location using latitude and longitude), geospatial calculations, cross-platform compatibility (such as Unity and Unreal game engines and JavaScript), open-source geospatial data standards, and data pipelines for geospatial information, such as 3D vector tiles. Moreover, they typically feature active community forums where users can find collaborative support for solving problems. During the project's planning phase, several map providers were evaluated by developing prototypes. The chosen map providers, namely Cesium, Mapbox, and Google's Photogrammetry 3D data, were assessed based on a range of features and services provided, such as availability of data, capability of geospatial calculations, and cross-platform compatibility. **Cesium**: Cesium, a prominent map provider, extends beyond its mapping services to offer various geospatial functionalities. Notably, it has pioneered the development of a standardized format for 3D geospatial objects known as 3D vector tiles. Furthermore, Cesium Ion, an associated service, provides hosting for these vector tiles and streamlines the process of programmatically converting datasets into 3D vector tiles. Unity and Unreal developers can visualize these datasets through Cesium's dedicated SDK. Additionally, Cesium offers certain basic 3D data for free, such as OpenStreetMap Building data. **Mapbox**: Mapbox, another map provider, stands out for its extensive capabilities. It offers 3D building data and the ability to dynamically load and view any location with precision by providing longitude and latitude coordinates. Beyond basic mapping, Mapbox includes valuable features such as live traffic data and bathymetry. Users can choose from various terrain options, including flat terrain and terrains with elevation data. Mapbox displays high accuracy in precision calculations when working with coordinates, allowing for precise placement of pointers and markers. Nevertheless, Mapbox has faced criticisms regarding the frequency of SDK updates, the last of which dated back to 2019. This has necessitated manual adjustments when integrating the SDK into new projects, such as deleting deprecated components and replacing deprecated methods. Despite this, Mapbox continues to provide support through its forums and offers a free tier during prototype development. **Google's Photorealistic 3D Tiles:** A unique offering for geospatial data comes from Google in the form of Photorealistic 3D Tiles. This dataset represents a 3D mesh model of the world, created from satellite imagery and Google Street View. Though experimental during the time of development, it exhibited impressive smoothness and precision. This dataset adheres to Cesium's open standard and is hosted on Cesium's platform, requiring Google's map API with an authentication key for access. One of its standout features lies in its remarkable precision when placing different objects on the terrain. These objects integrate with the landscape, even following its elevations. Google's Photorealistic 3D Tiles are observed to offer the best support for accurate visualization of spatial data that supports environmental decision making and disaster response, while providing limited capabilities to modify individual entities. In choosing a map provider for the application, Mapbox emerged as the preferred choice for several compelling reasons. Foremost, Mapbox boasts an abundance of data, ensuring a rich and comprehensive foundation for our visualization needs. The platform's free tier allows for substantial exploration and development work.