Lesson 10d1: Importing Data into LP360

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Detailed Description

LP360 is a family of tools for visualizing, manipulating and editing point cloud data and are offered both as an extension for ArcGIS, and as a standalone desktop platform for Window. By the end of this lesson, you will be able to open LiDAR point cloud LAS data files in the LP360 Viewer, visualize the data in 2-D and 3-D, change the visualization using toolbar functions, and turn on all or specific LiDAR point Classes.

 

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Image Dimensions: 1920 x 1080

Date Taken:

Length: 00:19:01

Location Taken: US

Transcript

Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

Lesson 10d1: Importing Data into LP360. LP360 is a family of tools for visualizing, manipulating and editing point cloud data and are offered both as an extension for ArcGIS, and as a standalone desktop platform for Window.

By the end of this lesson, you will be able to open lidar point cloud LAS data files in the LP360 Viewer, visualize the data in 2-D and 3-D, change the visualization using toolbar functions, and turn on all or specific lidar point Classes.

Before we begin, you will want to download some lidar data to use during our exercise.

For this lesson, we’ve conveniently packaged six tiles of LAS data into a zip file called “USGS_LPC_CO_SoPlatteRiver_Data_for_Lessons.zip” and loaded it to our FTP website. Please navigate to this location and download the zip package. Note that this package file is over 700 Mbytes and may take 10-15 minutes to download.

After you’ve downloaded the lidar data, extract the zip file into a folder on your local computer to use during this lesson.

The National Map has a download client where you can find USGS products to include elevation data such as lidar point clouds.

If you are interested in learning more about downloading products on The National Map, be sure to check out our training videos.

LP360 is available in six licensing levels with capabilities ranging from simple point cloud visualization, to more advanced QA/QC, classification and analysis functions. We are using the standalone LP360 Viewer license, version 2018.1.57.7 for this tutorial.

The standalone LP360 Viewer license is freely available through the manufacturer. If you do not already have the LP360 viewer on your computer, please visit their support site and click on the “Get Support” button below the LP360 logo.

Type LP360 in the subject line of the email and type “I am writing to request a license for the LP360 viewer” in the body of the email.  You will receive a license manager and instructions for setting up LP360. Your system administrator may need to assist you. Additionally, for supplementary information about LP360 Viewer Tools, please reference the tool guide.

Launch the LP360 Viewer.

When LP360 loads you will see the ‘View’ pane, the ‘Table of Contents’ pane, the ‘LP360 Toolbar,’ and the ‘Display and Navigation Toolbar’.

Toolbars can be toggled on and off through the ‘View’ menu. If you click on the ‘View’ menu, you should see checkmarks next to the ‘LP360 Toolbar,’ ‘Display and Navigation Toolbar,’ and the ‘Table of Contents.’ If not, toggle them on now.

LP360 is a point cloud tool, however, in addition to opening LAS files, it can also load vector and raster data with ease. To load LAS files, you can either click File> Open> LAS Files, or click the ‘Add LAS/Raster Layer’ button.

In the ‘Add Files’ window, click the green ‘Add’ button and browse to the location of the lidar point cloud LAS files that were downloaded from the FTP site. Click on the file named ‘USGS_LPC_CO_SoPlatteRiver_Lot5_2013_13SDD480395_LAS_2015 ‘ and click ‘Open’.

In the ‘Open Setting’ preferences, click the radio button to select ‘Open Read-Only.’ Under the ‘Load Setting,’ select ‘Load Files,’ and under ‘Options,’ toggle the ‘Pyramid’ option and accept the default ‘Thinning’ value of 16. Then click ‘OK.’

This lidar tile is in Apex Open Space park, just west of Golden, Colorado. After a few seconds you should see the one tile of lidar data displayed in the ‘View’ pane, and a LAS Layer_1 added to the ‘TOC’ tab of the ‘Table of Contents.’ The ‘LAS Files’ tab shows additional information about this layer. Under LAS Layer_1, we can see that this layer contains one file and the name of the lidar tile that we loaded in the previous step. The ‘Load’ icon next to the lidar tile name tells us that the lidar points are currently loaded. Double-clicking on this icon will unload the data and cause it to disappear from the ‘View’ pane. This is especially helpful when you have multiple tiles loaded. Double-clicking the ‘Load’ icon again will reload the data.

The ‘View’ pane defaults to displaying the full extent of the data. You can use the ‘Display and Navigation Toolbar’ to explore the data further. This tutorial will cover the most relevant buttons; however, you may refer to the LP360 Tool Guide for a more comprehensive reference.

This toolbar provides multiple options for Zooming in and out and panning through the data layer. The ‘Zoom In’ or ‘Zoom Out’ buttons enable you to zoom in or out of a spot of the map by left clicking in the ‘View’ pane, or by left-clicking and dragging a rectangle in the ‘View’ pane.

Additionally, if you want to move around in the ‘View’ pane without changing your zoom, you can use the ‘Pan’ button to maneuver around to a new area.

The ‘Zoom Previous’ button returns to the previous zoom level, and finally, the ‘Full Extent’ button returns to the default map view.

The ‘LP360 Toolbar’ enables us to easily change visualizations using the ‘Legend Types’ and ‘Draw Types’ drop-down menus.

‘Legend Types’ displays points based on attribute values such as elevation, classification, intensity and point source ID. The availability of various ‘Legend Types’ is dependent upon the attributes present in the loaded lidar tile. By default, LP360 visualizes the LAS point values using a ‘Display by Elevation’ rainbow color palette where blue corresponds to the lowest elevation, and red corresponds to the highest elevation values. Notice that the ‘TOC’ tab of the Table of Contents also displays ‘Elevation’ as the current Legend type.

Click on the ‘Legend Types’ drop-down menu and select ‘Display by Classification.’

The legend on the TOC tab now displays all possible point classifications.

Note that not all of these point classifications will be represented in our LAS tile. In fact, from the ‘View’ pane we can see that in our LAS file most of the points are classified as Ground (colored in orange), Unclassified (colored in gray), and High Noise (colored in pink).

Now click on the ‘Legend Types’ drop-down menu and select ‘Display by Intensity.’ This is displaying lidar points as a gradient from black to white based on the intensity of the return pulse. Intensity is a measure of the surface reflectance and will be higher (lighter colors) for surfaces with stronger reflectance back to the lidar sensor and lower (darker) for surfaces with less reflectance.

Up until this point, we have only been visualizing the LAS file based on point classifications. However, the ‘Draw Types’ drop-down menu provides additional options for viewing data as different surface types. Click the ‘Draw Types’ drop-down menu and select display the Triangulated Irregular Network or TIN surface.

This ‘Draw Type’ draws a TIN surface on-the-fly based on the attributes of the input lidar points. The ‘View’ pane is now displaying a continous surface derived from lidar point intensity values. We can now see a lot more detail of the landscape including trees, a rock quarry, and a road.

Now, use the “Legend Types” drop-down menu to view the original “Display by Elevation” legend as a TIN surface. Displaying the elevation values as a TIN surface gives us an excellent view of the topography of the area. However, notice how some of the finer features such as roads are harder to identify with this legend as compared with the previous ‘Display by Intensity’ legend.

LP360 provides the ability to apply intensity shading on top of the current display surface. Similar to the ‘Legend Types’ tool, the ability to use the ‘Apply Intensity Shading’ tool is dependent upon the existence of intensity values within your LAS dataset. Now click the ‘Apply Intensity Shading’ button to the right of the draw type button. You should now see an intensity shading applied to the elevation surface. The addition of intensity shading accentuates many of the finer features on the surface such as roads and striations in the rock quarry.

Though the ‘View’ pane is displaying a lot of detail on the surface, we can see on the ‘LP360 Toolbar’ that that our view is currently only displaying 1.56% of the data. At this scale it is not necessary to use 100% of the points to observe characteristics of the land surface. Additionally, thinning the data allows for greater performance while exploring the dataset.

However, LP360 does provide a “Force 100% Resolution” tool which will force all points to be drawn on the screen. Click the “Force 100% Resolution” button.

Because this is your first time using the ‘Force 100% Resolution’ tool, you should see the “Full Resolution Help Tip” pop up. The tool tip warns that since rendering 100% of the lidar points is very memory intensive, the number of points drawn may exceed the ‘maximum cache size’ allowed by this tool resulting in only a subset of the surface being generated. Since the ‘View’ pane is currently displaying the entire extent of our LAS data, this tool will fail to force 100% resolution on the entire tile. Note this tool tip will only pop up if this is the first time using the “Force 100% Resolution” button during this session. Click “No” to exit the tool tip.

Using the ‘Zoom In’ tool on the ‘Display and Navigation Toolbar’ zoom in on the building in the lower left corner. This is the Mother Cabrini Shrine in Golden, Colorado. The drop-down menu below the ‘View’ pane shows the current scale of the display. This will be grayed out in the LP360 Viewer license software version. Using the ‘Zoom In’ tool, zoom in until the scale display reads just under 1:1000.

 Now that we are zoomed into a smaller region, click the ‘Force 100% Resolution’ button again. On the ‘LP360 Toolbar’ you should now see that the ‘View’ pane is displaying 100% of the data.

Displaying 100% of the data on the subset of our LAS tile significiantly increases the details we can observe in the the ‘View’ pane. The outlines of the buildings and hedges are now sharply defined and we can even make out the lines in the parking lot.

Now de-select the ‘Force 100% Resolution’ button and use the ‘Full Extent’ button on the ‘Display and Navigation Toolbar’ to return to the full extent of the LAS tile.

LP360 also makes it very simple to view the data in 3D. Start by activating the ‘Viewer Integration Toolbar.’ This is accomplished by clicking the drop down ‘View’ menu, and clicking the ‘Viewer Integration Toolbar.’ The ‘Viewer Integration Toolbar’ will now appear in the LP360 window.

To use the ‘3D Window’, click the ‘Toggle 3D Display’ button. By default, the ‘3D Window’ opens up without any data in it.

You can also open the ‘3D Window’ through the ‘View’ drop-down menu. However, since your 3D window is already open, you should see a check mark next to the ‘3D Window’ option showing that it is active. Now toggle the ‘Table of Contents’ to hide it from view.

We will now select the data to display in the ‘3D Window.’ Click the ‘Draw 3D Viewer Extent’ button. This will activate a selector cursor in the 2D ‘View’ pane that can be used to choose data to display in the ‘3D Window’.

We will look a the rock quarry in the lower right hand corner of the LAS tile. Draw an extent box over the quarry by left clicking the cursor and dragging box over the area of interest. When you let go of the cursor you will see a new white bounding box drawn in the 2D window. The ‘3D Window’ is now displaying a 3D rendering of the point cloud data contained within that bounding box. We can explore the data in the 3D view using the mouse buttons. To Zoom, click and hold the left mouse button while moving your mouse forwards and backwards. To rotate the 3D view, click and hold the right mouse button and drag the tile around to a new angle.

Similar to the 2D ‘View’ pane, the ‘3D Window’ also enables us to visualize data by changing ‘Draw Types’ and ‘Legend Types’. On the ‘3D Window’ toolbar, use the ‘Draw Types’  drop-down menu and select ‘Display TIN Surface.’

Also on the ‘3D Window’ toolbar, ensure that the button that ‘Toggles hillshading of the TIN surface’ is turned on.

Now as you zoom and pan around in the ‘3D Window’ you will notice large spikes protruding from the surface. Since we are displaying all the data point classifications, these spikes show the high noise point classifications present in our data.

LP360 provides several methods to filter data in order to only display the data that are of interest to us. Additionally, 2D and 3D filters are separate, so you can change filter parameters in one window independently of the other.

First, in both the 2D and 3D view windows, you will see a drop-down menu with the ‘Filter’ currently set to ‘All Points.’ The ‘Filter’ drop-down option provides several pre-set options such as ‘Ground’ and ‘Canopy.’ Keep in mind that the availability of these filters will depend on the classifications within your LAS tile.

Using the ‘Filter’ drop-down in the 3D view, select ‘Ground.’ The ‘3D Window’ now only displays points that have been classified as ‘Ground’.

Next, we can also select points of interest by changing the display properties for our LAS tile. Click on the ‘Display Properties’ icon in the 3D window. This will open a ‘Viewer Properties’ window for the LAS tile. The ‘Viewer Properties’ window provides a lot of options to customize point symbology and point filters which are beyond the scope of this tutorial.

In the ‘Viewer Properties’ window, click on the ‘Display Tab.’ This will open the ‘Points Filter’ Tab showing the ‘Classifications’ tab. Be sure that the ‘Use Points Filter for TIN’ option is toggled on, if not, toggle it on now. This ‘Classifications’ tab displays the ‘ASPRS Class Values and Names’ that may be present within our LAS dataset. Notice that since we selected the pre-defined ‘Ground’ filter in the previous step currently only Class 2 ‘Ground’ and Class 8 ‘Reserved’ are toggled on.

 In the ‘Classifications’ tab toggle on Class 1 ‘Unclassified’ and then click ‘Apply.’ In the ‘3D Window’ you should now see sparse vegetation appear on the ground surface. The ‘Classifications’ tab provides complete control over which point classifications to view or exclude from the view. Click ‘Cancel’ to exit the ‘Viewer Properties’ window.

Now, click ‘Applying Intensity Shading’ on the ‘3D Window Toolbar.’ As we saw in the 2D view, applying intensity shading sharpens fine surface details such as the quarry striations and the vegetation.

In addition to the 2D and 3D views, LP360 Viewer provides profile view options which can be useful for further data exploration. To simplify the view interface, close the 3D view window by deselecting the ‘Toggles the 3D Window’ button.  Now, on the ‘Viewer Integration’ Toolbar, click the ‘Toggle Profile Window’ button to activate the ‘Profile View’.

The ‘Profile View’ window will appear at the bottom of the LP360 Viewer window. Select the ‘Draw the Profile Box in 2D View’ and ‘Draw the Profile Center Line in 2D View’ buttons.

 Now, click the ‘Draw a Profile Line’ button. To create a profile, in the 2D ‘View’ pane first click on a hill on one side of the valley, then move your cursor to a hill across the valley and click again thereby creating the center line for the ‘Profile View’. To adjust the width, move your cursor perpendicular to the center line. When you are satisfied with the width, click a third time to make your selection. The points contained within your ‘Profile Box’ are now displayed in the ‘Profile View’.

Now, enlarge the ‘Profile View’ by hovering your cursor at the top of the pane until a resize icon appears, then click and drag the bar up to resize the window until you can view the extent of the profile.

As with the 2D and 3D View windows, the ‘Profile View’ also contains the ‘Legend Types’ menu and the ‘Display Properties’ menu. The ‘Profile View’ is another convenient method to explore point classifications and attributes contained while simultaneously viewing the underlying topography of the surface.

You’ve finished Lesson 10d1: Importing Data into LP360.

In this lesson, we discussed how to load a single LAS file in LP360, explore the data in 2D, 3D and Profile views, and use the LP360, Display and Navigation, and Viewer Integration Toolbars. We also learned how to filter lidar data by classification and apply symbology based on lidar point attributes.