Extract linear features from point clouds

After using the “Point Cloud Terrain Analysis” and “Point Cloud Modeling” tools in InfraWorks, we can draw in break lines, paint lines and more in 2D and 3D. 

There are two methods to do this:

• Automatic: Define two points on the target road to have InfraWorks automatically generate the linear feature from the point cloud data.

• Manual: Position points along the target road in the point cloud to identify and create a linear feature. Use the manual method for accurate linear extraction of complex area.

IMPORTANT: Before you can model linear features, you must use the “Point Cloud Terrain” tool to process data to extract features from a point cloud.

 

Let’s get started:

 

1. In InfraWorks, we’ve zoomed into an intersection of our model. Select the “Style Palette” by clicking on the Manager Tab of the Ribbon, going to the Content panel and selecting Style Palette. 

 

2. Select the “Linear Feature” from the palette.

3. Add a new “Linear Feature” by selecting the “+” sign.

4. A window titled “Define New Linear Feature” will appear. Select a “Line Type”. 

For our example: we’re going to choose 

• Line Type: “Breakline”

• Feature Code: “EA”

• Width: “0.5’”

• Color: Red

5. Select “OK” and name the “Linear Feature” in the “Style Palette”. In our example, we’ve named ours “Edge of Pavement”.

6. Now select “Linear Feature Extraction” from the left of the screen. 

7. The panel will appear at the right of the screen. You have two options: Manual and Automatic.

First, we’ll do manual.

1. Simply switch off “Automatic” under “Mode”.

2. Select the “Linear Feature” we just created by clicking on the “Linear Feature” image next to “Manual Style” and selecting “More Styles”. Find the new “Linear Feature” and select it.

3. Now select in the point cloud an edge of pavement and hit “Enter” to select. This process can be a little time consuming, but it is reading the model.

4. Repeat the process as needed.

5. To edit the line, you can select the line and use grips to change the position of a point.

6. To add a point, right-click and select “Add Point”.

7. To remove a point, click on the point and select “Remove Point”.

8. To see a cross section view, right click on the point and select “See Cross Section View”. This will bring up a “Linear Feature Cross Section” window with a cross section of the point. If you edit in this window, it will edit the feature line in the model as well.

Automatic:

1. In the “Extract Linear Feture New” panel, select “Automatic” under “Mode”. 

2. We want to add in some paint lines. So, click on the “Linear Feature” image next to “Manual Style” and select the “Paint Stripe”.

3. Select along a yellow paint line in one of the roads and double-click on the next selection – no need to follow the line. It’s going to read that point cloud model and try its best to find the “Linear Feature” and follow that paint line automatically.

 

4. To see a cross section view, right click on the point and select “See Cross Section View”. This will bring up a “Linear Feature Cross Section” window with a cross section of the point. If you edit in this window, it will edit the feature line in the model as well.

5. You’ll notice, sometimes the automatic line will veer off. To fix this, double-click on the nearest point and drag and drop it.

 

Now we can take these linear features, export them out and use them in Autodesk Civil 3D.