Displaying LAS datasets as a surface in ArcMap

LAS datasets can be rendered as triangulated surfaces in ArcMap using the flexibility of symbology options available for TIN-based surface layers. For example, a bare-earth surface can be symbolized by degree slope, or a first-return surface can be symbolized using the graduated color ramp of the elevation renderer. The LAS dataset's surface may be displayed using elevation, slope, aspect, or contour lines like TIN and terrain datasets. Any LAS filters or surface constraints that are enabled would be honored in the resulting triangulation of the LAS dataset.

The LAS dataset offers quick access to a handful of common renderers through the LAS Dataset toolbar, with advanced access being provided in the Layer Properties dialog. This toolbar also contains the LAS Dataset Profile View and LAS Dataset 3D View tools which enable 3D visualization within ArcMap. The LAS Dataset Profile View window will always display the LAS dataset points even when used on a surface.

How to display the LAS datasets as a surface in ArcMap

The LAS Dataset toolbar provides a quick way to display a LAS dataset as a surface. You can select from several symbology renderers to show the triangulated surface by elevation, slope, aspect, or contours. The LAS Dataset toolbar also provides access to LAS Dataset Profile View or LAS Dataset 3D View to view the LAS dataset surface.

To use the Display As TIN drop-down menu option to select a surface display renderer, follow the steps outlined below:

Steps:

1. Click the Add Data button from the Standard toolbar and browse to the LAS dataset. Click Add to add the LAS dataset layer to the table of contents in ArcMap.
2. Add the LAS Dataset toolbar to the display in ArcMap by right-clicking the main menu and clicking LAS Dataset.
3. Click the Display As TIN drop-down menu to choose a specific surface renderer to display the LAS dataset surface. Keep in mind that only one renderer can be applied to the surface at once.
   
   • Elevation
   • Aspect
   • Slope
   • Contour

Note:

If any LAS files that are referenced by the LAS dataset are moved, renamed, or deleted the path stored in the LAS dataset will be broken and the LAS file will not display. The extent of the LAS file in ArcMap will show a different symbology once the view is refreshed if the referenced file has been moved, deleted or renamed will not be displayed.

How to change surface display properties for a LAS dataset

Much like a TIN or terrain dataset layer, the LAS dataset layer can have one or more renderers associated with it. To display your LAS dataset layer as a surface, simply select a face-based renderer from the list. Using Layer Properties, you can have more than one renderer applied to the LAS dataset at one time.

To select a renderer for a LAS dataset surface layer, follow these steps:

Steps:

1. Right-click the LAS dataset layer in the table of contents and click Properties.
2. Click the Symbology tab.
3. Remove (or uncheck) any existing renderers.
4. Click Add to open the Add Renderer window.
5. Choose one of the surface-based renderers from the list:
   • Contour with the same symbol
   • Face aspect with graduated color ramp
   • Face elevation with graduated color ramp
   • Face slope with graduated color ramp
   • Face tag value grouped with unique symbol
   • Faces with the same symbol
6. Click Add and click Dismiss to close the Add Renderer window.
7. Click OK.

How to preview a LAS dataset surface in a profile view in ArcMap

LAS Dataset Profile View allows you to view and manipulate your LAS dataset points in a 2D profile window. To learn more about LAS Dataset Profile View, see LAS Dataset Profile View.

When the LAS Dataset Profile View tool is used on a surface, the LAS Dataset Profile View window displays points.

To view the LAS dataset surface points in LAS Dataset Profile View, follow the steps outlined below:

Steps:

1. Click the LAS Dataset Profile View button from the LAS Dataset toolbar.
2. With the cross-hairs active, click a location on the surface that represents the starting point of the LAS dataset profile graph.

   A small dialog box appears, interactively showing the current length of the line. Use the SHIFT key to set straight vertical or horizontal lines. Press the ESC key to cancel.

3. Click a location on the surface that represents the ending point of the LAS dataset profile graph.

Once an ending point has been selected, a selection box appears allowing you to move the pointer until the box is at a desired profile width. The actual dimensions and point count for the selection box are displayed in a small dialog box in the ArcMap display window. These values change interactively as you move the pointer over the point set. The units of the displayed width correspond to the coordinates of the data being used for the analysis. When a maximum point count is reached, you cannot make the selection box any larger.

4. Click a third location to represent the width of the profile graph.

The profile graph is displayed in a separate window. The LAS Dataset Profile View window allows you to view and edit the classification of the lidar points of the LAS dataset. To learn more about the editing tools available in LAS Dataset Profile View, see LAS Dataset Profile View or An overview of editing LAS datasets.

How to preview a LAS dataset surface in a 3D view in ArcMap

LAS Dataset 3D View allows you to view your LAS dataset surface in a 3D window. To learn more about LAS Dataset 3D View, see LAS Dataset 3D View.

To view LAS dataset points in LAS Dataset 3D View, follow the steps outlined below:

Steps:

1. Zoom to set the desired display extent to be shown in LAS Dataset 3D View.
2. Click the LAS Dataset 3D View button from the LAS Dataset toolbar to launch LAS Dataset 3D View.

The 3D display of the LAS dataset opens in a separate window.