Digitizing features on a surface

Creating 3D features during an edit session by directly digitizing on a surface

In ArcScene and ArcGlobe, you can drape your 2D features on a surface (such as a raster or TIN) to visualize those features in 3D. You can also create new features by digitizing directly on the underlying surface. The new features you create do not have to be z-aware, as they will still be displayed in 3D because the layer is draped on the surface. Using 2D features when digitizing directly on a surface is recommended because it simplifies data storage, and the height of your features will always be in sync with your surface data, even as incremental updates improve the surface.

Although similar, the editing process for digitizing new features over a surface is slightly different in ArcScene in ArcGlobe. Each workflow is detailed below.

Getting started tips

• You can either use the Add Data button or the Catalog window to drag and drop your data into the 3D view.
• Make sure the 3D Editor toolbar is already added to your display. Click Customize > Toolbars if you need to add it.

How to digitize features on a surface in ArcScene

Steps:

1. Start ArcScene and add the 2D feature class (point, line, polygon) you want to create new features for.
Each 2D feature layer you want to digitize on a surface must have its base height (elevation source) set to the surface. This is explained in step 3.
2. Add the surface data that you want to drape the features on, for example, a TIN or raster.
Optionally add any imagery that you want to use as the backdrop for digitizing from. You only require a surface layer to digitize from, but sometimes an image draped on the surface can make the view more realistic. The image's layer properties will need to be set so that the base height source is the surface layer.
3. Set the base heights for the feature layer to the surface data.
   1. Double-click the layer to open the Layer Properties dialog box.
   2. Click the Base Heights tab.
   3. Select Floating on a custom surface and ensure your surface layer is selected in the drop-down list.
The surface will act as the elevation source for any newly created features.
4. On the 3D Editor toolbar, click the 3D Editor drop-down list and click Start Editing.
If the layers in your table of contents come from more than one source, you may be prompted to choose the layer or workspace to edit.
5. If you prefer, now would be a good time to open the Snapping Environment window to set snapping properties. Open the window by clicking 3D Editor, expand the Snapping side menu, then click Snapping window.
6. Choose a feature template and select the edit construction tool from the Create Features window to begin creating new features.
7. Click the surface to place vertices for new features.
For polylines and polygons, double-click the last vertex to finish the sketch.
8. When you are finished digitizing features, click 3D Editor and click Stop Editing.
You will be prompted to save or reject your edits.

How to digitize features on a surface in ArcGlobe

Steps:

1. Start ArcGlobe and add the 2D feature class (point, line, polygon) you want to create new features for.
By default, the layer is automatically added to the draped category in the table of contents.
2. Add the surface data that you want to drape the features on, for example, a TIN or raster or an elevation service.
Optionally add any imagery that you want to use as the backdrop for digitizing from. You only require a surface layer to digitize from, but sometimes an image draped on the surface can make the view more realistic. The image's layer properties will need to be draped on the surface of the globe.
The surface will act as the elevation source for any newly created features.
3. On the 3D Editor toolbar, click the 3D Editor drop-down list and click Start Editing.
If the layers in your table of contents come from more than one source, you may be prompted to choose the layer or workspace to edit.
4. If you prefer, now would be a good time to open the Snapping Environment window to set snapping properties. Open the window by clicking 3D Editor, expand the Snapping side menu and click Snapping window.
5. Choose a feature template and select the edit construction tool from the Create Features window to begin creating new features.
6. Click the surface to place vertices for new features.
For polylines and polygons, double-click the last vertex to finish the sketch.
7. When you are finished digitizing features, click 3D Editor and click Stop Editing.
You will be prompted to save or reject your edits.

Important Notes

• It is important to note that while the newly created 2D features are being displayed on the surface, these features cannot and do not contain z-values imported from the surface. If you need to do this—for example, as a prerequisite for a certain analysis task—then this can be achieved by running the Interpolate Shape geoprocessing tool against your most up-to-date surface data.
• If required, you can digitize 3D features directly on to a surface using the workflows described above. There are a few behavioral differences, the most important of which is that 3D lines and polygon boundaries will automatically included intermediate 3D vertices based on the resolution of the elevation surface. For more information, see Digitizing 3D feature vertices.