Elevation surfaces define height values across the extent of a map or scene. The most common use for elevation surfaces is to define the elevation source for rasterized content and "on-ground" vector symbols, but surfaces are also used to define heights when editing features. For example, when you create features, you can specify the xy-location as you edit, but the z-value of the feature can be derived from an elevation surface.
To edit z-aware data with side-by-side views of a map and a scene, use the same elevation source set in both the map and the scene.
A scene always has at least one elevation surface, which represents the ground. You cannot remove the ground surface, but you can replace its elevation source. You can also add additional custom elevation surfaces. Examples of custom elevation surfaces include one that defines the depth of a geological strata, or one that defines the height of a restricted airspace. You can set the height of feature layers to be drawn on the ground, relative to the ground, or at an absolute height from the elevation surface.
To add an elevation source to the ground surface, use the Add Data menu from the Map tab, select Elevation Source and browse to the desired elevation data. This adds the elevation source to the ground and makes it visible in the Contents pane. You can optionally use the context menu for the Elevation Surfaces group in the Contents pane to add a new custom surface and configure its source. Any appearance or behavior settings for elevation surfaces, such as navigation underground, are on the Appearance tab for the selected surface layer.
Each elevation surface can have one or more elevation data sources that define the height across the surface. An elevation source can be a TIN, an image surface (LERC image service), or a raster dataset. LAS datasets and terrain datasets cannot be used as an elevation source. In areas where the elevation source values overlap, the value from the elevation source listed first in the Contents pane is used to define the surface. You can move elevation sources within the elevation category by dragging and dropping it with the associated elevation surface, or to a different elevation surface. Also, an elevation surface can have no elevation source at all. In this case, all elevation surface values are defined at an absolute, constant height of 0.
Ground elevation surface
Each map or scene contains a predefined elevation surface called Ground that cannot be removed. The default elevation source for this surface is a cached elevation image service, WorldElevation3D/Terrain3D. If you are not connected to the Internet, you will not have access to this service and the ground elevation will be 0. You can optionally add a local elevation source to the ground elevation surface.
Navigate below ground
Because Ground represents the surface of the earth, you can apply navigation rules to it. By default, navigation below ground is disabled. It is often unnecessary to go below ground and can be disorienting when you go there by accident. If, however, your scene contains data that correctly belongs underground—such as subsurface utility pipes or geological features—you can enable below-ground navigation. In this mode, the height list in the lower corner of the scene view shows negative values when you're beneath the ground surface. You can enter negative numbers directly, such as -100m, to navigate the camera vertically below the surface.
- In the Contents pane, select the Ground elevation surface.
- On the Appearance tab, check Navigate Underground tab.
Custom elevation surfaces
In addition to the ground elevation surface, you can add additional custom elevation surfaces. Custom elevation surfaces must have a valid elevation source.
An elevation source contains the data that defines the elevation surface. An elevation surface can have more than one elevation source, and you can combine different types together. Local elevation sources can be either a raster that contains elevation information or a TIN dataset. You can also use a LERC image service as elevation sources. You can find elevation layers on ArcGIS Online by searching for the keyword elevation. If you use custom image services, make sure you have elevation defined as the service type.
You cannot add the same elevation source if it is already present in the elevation surface. You can share an elevation source of type raster file as elevation layer.
The order of elevation sources in the elevation surface determines the order they are used, so the data source with the highest resolution should be placed highest in elevation source order. When you navigate to an area of your map or scene that is outside the extent of the first (highest resolution) elevation source, the next elevation source in the list will be used, and so on.
Add a custom elevation surface
- In the Contents pane of a scene, right-click on Elevation Surfaces, and click Add Elevation Surface.
You can change the name of the elevation surface by double-clicking on the newly added elevation surface.
- Right-click on the new surface and select Add Elevation Source .
- Browse to a valid elevation source on your file system or on ArcGIS Online.
Valid elevation source formats are elevation layers, imagery layers, raster datasets, and TIN datasets.
Specify the Vertical Units of the elevation source. Set the vertical unit of the elevation source to match the elevation units of the scene to avoid vertical distortion. If mountains and valleys look about three times taller than they should, you may have a scene defined in meters but an elevation source defined in feet. In this case, change the vertical unit of the elevation source to meters. The Elevation Units of a scene are set on the General tab of the Map Properties dialog box.
Properties of elevation surfaces
You can optionally apply a vertical exaggeration to each elevation surface. If the surface is very flat, set the vertical exaggeration of the surface to a value greater than 1 to emphasize vertical differentiation.
Each surface can have a surface color. By default, the color of the ground surface is white, and the default of custom surfaces is no color. Use No color when you need a surface to define elevation, but you do not want it to draw. When you want the surface to draw as a physical surface in the map (scene), choose a color, and optionally check Shade surface relative to the scene's light position to emphasize variations in relief. You typically do this when you do not have a basemap in the scene.