An ArcGIS Map contains references to layers of geographic content and is the foundation for all visual mapping applications in the ArcGIS Maps SDK for Unreal Engine. It combines a basemap (for visual context) and data layers (for geographic data).
To build an app with ArcGIS Maps SDK for Unreal Engine, you define an ArcGIS Map, a camera (to display geographic data and to navigate around), and environments such as sky and light.
Key concepts
In ArcGIS Maps SDK for Unreal Engine, an ArcGIS Map can contain a basemap, data layers, and elevation for use in 3D. This is different from standard ArcGIS terminology where a map is used in 2D while a scene is used in 3D.
In addition to the basemap and data layers, you also specify the type of ArcGIS Map (global or local), the origin position, and an elevation surface (for topographic context in 3D).
Global scene
A global scene is created using the global map type to display your 2D and 3D content on an ellipsoid.
A global scene is useful when you want to understand or contextualize phenomena that wrap around the ellipsoidal surface of the earth, such as global weather measurements, airline traffic paths, and shipping lanes.
Local scene
A local scene is created using the local map type that projects the terrain and layers on a planar surface rather than on an ellipsoid.
Local scenes can be used for displaying or analyzing data at the local or city scale and are valuable for urban planning and visualizations when you want to view defined areas such as campus facilities or building developments. They can also be used to represent the entire world, and have the option of using a fixed extent to clip with rectangular or circular shapes.
Origin position
To place geographic content within a scene, you must specify where the 0, 0, 0 origin coordinate of the game engine space is in the real-world coordinate space. You do this when you create an ArcGIS Map.
You can specify an origin position anywhere within a spatial reference's coordinate space. See Spatial references for more details about working with spatial references.
Values for Origin position
- X (Longitude): Specifies the east–west position of a point on the earth's surface. A projected position value for projected coordinate systems or a longitude value for geographic coordinate systems.
- Y (Latitude): Specifies the north–south position of a point on the earth's surface. A projected position value for projected coordinate systems or a latitude value for geographic coordinate systems.
- Z (Altitude): The vertical distance of the camera above the terrain.
- Spatial Reference: The spatial reference Well-Known ID (WKID) for the horizontal (geographic or projected) and optional vertical (gravity-related or ellipsoidal) coordinate systems.
Depending on your app requirements, choose between a global or local scene when you create an ArcGIS Map. Global and local scenes each use layers to display the distinct types of geographic data. The data is typically provided from the basemap layer service and other data services.
Camera
Cameras are essential for displaying your game to the player. In ArcGIS Maps SDK for Unreal Engine, a camera is used for loading GIS data into your scene.
Elevation
Elevation surfaces add to 3D visualizations by creating relief in your 3D scene. They define height values across the extent of your ArcGIS Map's content, and ArcGIS Map will drape layers on top of the elevation surface.
In most cases, elevation data is read from an elevation service, but can also be read from an map tile package stored locally.
Creating an ArcGIS Map
ArcGIS Map is a container of GIS content and sends information to Unreal Engine about what and how it should be rendered.
The Modes Panel UI and ArcGIS Map Component contain the settings for the Map Type, Spatial Reference, and Origin Position. If no spatial reference is defined for an ArcGIS Map, it is defined by the basemap. When you don't set a basemap, the spatial reference is defined by the first layer loaded.
You can manually specify the spatial reference to match the basemap and other layers using the Modes Panel UI and ArcGIS Map Component or using the Blueprints or C++ API to create an ArcGIS Map. Spatial data is automatically reprojected if necessary to match the spatial reference of the ArcGIS Map.
To create an ArcGIS Map:
The Modes Panel UI contains the settings for Map Type, Spatial Reference, and Origin Position in the Map page.
- Click on the Map tab, and find the Map Type section to select
GlobalorLocal. - In the Spatial Reference, set the spatial reference WKIDs for the horizontal and optional vertical coordinate systems.
- In the Origin Position, set the position values and spatial reference WKIDs for the horizontal and optional vertical coordinate systems.
- Click the Create button.
When an ArcGISMap is created in the scene, the UI displays the existing configured values of the selected ArcGISMap. You can modify these values while in Editor mode.
If you select Local, you can configure an extent. For more information about setting up an extent, see local scene.