This tutorial demonstrates how to create a AutoCAD Civil 3D point cloud object from imported LiDAR data, modify the object display, and then create a surface from a subset of point cloud points.
For more information, see the AutoCAD Civil 3D Help topic Understanding Point Cloud Objects.
Exercise 1: Importing Point Cloud Data
In this exercise, you will import a LiDAR data file to create an AutoCAD Civil 3D point cloud object.
For more information, see the AutoCAD Civil 3D Help topic Creating Point Cloud Objects.
1 Open Point Cloud-1.dwg, which is located in the tutorial drawings folder (page 819).
2 Click Home tab ➤ Create Ground Data panel Create Point Cloud.
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Specify basic point cloud information
1 In the Create Point Cloud dialog box, on the Information page, specify the following parameters:
■ Name: Point Cloud - Tutorial
■ Point Cloud Style: Single Color
■ Point Cloud Layer: V-SITE-SCAN 2 Click Next.
Specify the source data
1 On the Source Data page, under Source Data, select Create A New Point Cloud Database.
2 Under Select A Point Cloud File Format, select LAS.
3 Under Files To Be Imported Into The New Point Cloud Database, click .
4 In the Select File dialog box, navigate to the tutorial folder (page 820). Select Point Cloud.las. Click Open.
5 Under New Point Cloud Database, under Specify New Point Cloud Database, click .
6 In the Select File dialog box, navigate to the My Civil Tutorial Data folder (page 819). For File Name, enter Point Cloud - Tutorial.isd. Click Open.
NOTE The Point Cloud Database Coordinate System and Current Drawing’s Coordinate System settings should match. The coordinate system is not set in this tutorial, but the settings come from the following sources:
■ Point Cloud Database Coordinate System: This value is taken from the point cloud source file. Click to change the coordinate system when the data is imported into the point cloud database.
■ Current Drawing’s Coordinate System: This value is taken from the Drawing Settings dialog box, on the Units and Zone tab.
7 Click Next.
Verify the point cloud parameters and create the point cloud object
1 On the Summary page, expand the collections in the Property table, and ensure that the properties match what you specified earlier in this exercise.
If the property values do not match, use the links on the left side of the dialog box to return to the previous pages.
2 Click Finish.
A dialog box notifies you that the point cloud database is being processed in the background, and that you may continue to work in the drawing.
3 Click Close.
After a few minutes, a notification appears in the status bar, indicating that the point cloud database has been processed, and the point cloud object has been created.
Examine the point cloud object
1 In the status bar notification, click Click Here To Zoom.
The drawing window zooms to the point cloud object.
2 Zoom in until you can see the points that make up the point cloud.
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Examine the points. The point cloud points are stored in the point cloud database, and they cannot be manipulated individually.
3 Zoom to the extents of the point cloud object.
4 Click View tab ➤ Views panel ➤ SE Isometric.
A three-dimensional view of the point cloud object is displayed. the white box that surrounds the point cloud is the bounding box, which identifies the extents of the point cloud object. The size and geometry of the bounding box component depend on the point cloud object minimum and maximum coordinate values. The bounding box serves as a point cloud object proxy when the point cloud source data is not accessible.
5 Click View tab ➤ Views panel ➤ Top.
To continue this tutorial, go to Exercise 2: Working with Point Cloud Styles (page 50).
Exercise 2: Working with Point Cloud Styles
In this exercise, you will use styles to view the point cloud object in different ways, as well as to filter the display of imported point cloud data.
For more information, see the AutoCAD Civil 3D Help topic Displaying and Stylizing Point Clouds.
This exercise continues from Exercise 1: Importing Point Cloud Data (page 47).
Display point cloud points by elevation 1 In the drawing, select the point cloud.
2 Click Point Cloud tab ➤ Modify panel ➤ Point Cloud Properties drop-down ➤ Point Cloud Properties.
3 In the Point Cloud Properties dialog box, on the Information tab, under Point Cloud Style, select Elevation Ranges.
This point cloud style displays point cloud points as a specified color, based on their elevation value.
4 On the Elevation Ranges tab, click Reset From Style.
This action specifies that the point cloud style parameters determine the display properties of the point cloud.
5 Click OK.
The point cloud now shows the major differences in elevation between the point cloud points. In the following steps, you will view point cloud points by the classification code that was assigned to them as they were created.
Display point cloud points by classification 1 In the drawing, select the point cloud.
2 Click Point Cloud tab ➤ Modify panel ➤ Point Cloud Properties drop-down ➤ Point Cloud Properties.
3 In the Point Cloud Properties dialog box, on the Information tab, under Point Cloud Style, select LIDAR Point Classification. Click OK.
The point cloud now shows the color-coded point cloud points. This is a useful way to see different features that were captured during the scan.
In the following steps, you will adjust the point cloud style to filter unwanted features from the point cloud.
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Filter points by classification
1 In the drawing, select the point cloud.
2 Click Point Cloud tab ➤ Modify panel ➤ Point Cloud Properties drop-down ➤ Edit Point Cloud Style.
3 In the Point Cloud Style dialog box, on the Classification tab, click .
For this exercise, you will specify that the style display only the ground points.
NOTE The classifications in this table are based on ASPRS American Society of Photogrammetry and Remote Sensing standards.
4 In the LIDAR Classification table, select the 2 Ground check box.
As shown in the Color column, the point cloud points that are assigned the 2 classification are displayed as brown.
5 Click OK.
In the drawing, only brown, Ground points are displayed. In the next exercise, you will learn how to create a AutoCAD Civil 3D surface from this subset of point cloud points.
NOTE If the display does not change, enter REGEN on the command line.
To continue this tutorial, go to Exercise 3: Adding Point Cloud Data to a Surface (page 53).
Exercise 3: Adding Point Cloud Data to a Surface
In this exercise, you will create a surface from a subset of imported point cloud points, and then examine the relationship between the point cloud and surface objects.
For more information, see the AutoCAD Civil 3D Help topic Adding Point Cloud Points to Surfaces.
This exercise continues from Exercise 2: Working with Point Cloud Styles (page 50).
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Adjust the visible point density
1 In the drawing, select the point cloud.
On the Point Cloud tab, on the Point Cloud Tools panel, the Point Density slider enables you to adjust the density of points displayed at once for all point clouds in the drawing view. When the slider is set to 100, the drawing will display either 750000 point cloud points, or all the point cloud points that exist in the visible area, whichever is less.
2 In the field next to the Point Density slider, enter 10. Press Enter.
The density of the points that are visible in the visible drawing area is reduced.
Add point cloud points to a surface
1 Click Home tab ➤ Layers panel ➤ Layer drop-down. Next to
_TOPO-BOUNDARY, click . Click in the drawing to exit the Layer list.
A closed polygon is displayed in the drawing. In the following steps, you will create a surface from the point cloud points that are inside this polygon.
2 In the drawing, select the point clout object.
3 Click Point Cloud tab ➤ Point Cloud Tools panel ➤ Add Points to Surface.
4 In the Add Points to Surface wizard, on the Surface Options page, specify the following parameters:
■ Name: Point Cloud Surface
■ Surface Style: Contours 0.5’ and 2.5’ with Points
NOTE You may also add the point cloud points to an existing surface in the current drawing.
5 Click Next.
6 On the Region Options page, under Specify a Region Option, select Object.
7 Click Define Region in Drawing.
8 In the drawing, select the polygon.
9 Click Next.
10 On the Summary page, expand the collections in the Property table, and ensure that the properties match what you specified earlier in this exercise.
If the property values do not match, use the links on the left side of the dialog box to return to the previous pages.
11 Click Finish.
The gray surface contours and cyan surface points are displayed in the drawing, and a surface object is displayed in Toolspace on the Prospector tab.
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Modify the surface
1 Press Esc to deselect the point cloud object.
2 In Toolspace, on the Prospector tab, expand the Surfaces collection.
Right-click Point Cloud Surface. Click Rebuild - Automatic.
3 Zoom in to the surface.
NOTE As you zoom in, AutoCAD Civil 3D honors the point cloud density setting by displaying more point cloud points.
4 Select the surface.
5 Click TIN Surface tab ➤ Modify panel ➤ Edit Surface drop-down ➤ Delete Point.
6 On the command line, enter C to use crossing selection.
7 Draw a window around a group of cyan points. Press Enter.
The cyan surface points are removed, and the contours update. The brown point cloud points are still present because they are stored in the point cloud database, and are not affected by edits to the surface.
8 Press Enter to end the command.
9 In the drawing, select the polygon that you used to create the surface.
10 Select one of the grips, and drag it to a new location. Click to place the grip.
The surface updates to include the point cloud data that is enclosed in the new area.
Further exploration: On the right-hand side of the surface, the surface contours extend beyond the extents of the polygon. The surface triangulated outside that side of the surface. You may use the polygon as an outer boundary to prevent triangulation outside the surface extents. For more information, see the Adding an Outer Boundary to a Surface (page 70) exercise.