Bridging the Gap Between Drone and CAD
Drones are everywhere and drone data is at everyone’s fingertips! The fact that this simple machine flies through the air, captures photos, and then somehow returns usable, actionable data is just fantastic. But what do we do in AutoCAD® and Civil 3D® with the data? We can bring in the ReCap file, but then what? Connect some dots, draw some lines, but it all just seems too much of a manual process.
I’ve been in the reality capture industry for years and have really taken to the drone space, but have always struggled with creating a useable existing conditions map from the data within Civil 3D, until now!
Recently I was introduced to Virtual Surveyor (https://www.virtual-surveyor.com/) and feel that this is one of the best, if not THE best, tools out there to bridge that gap between drone and CAD. This article looks at some of the many features within the software.
The creation of a new project is very simple and takes only a few minutes regardless of project size. All you need is a raster image file (.tiff) and an elevation file such as a DEM. Combine those two and you are off and surveying in your virtual world. With software such as Pix4D and 3DR SiteScan, these formats are immediately available upon successful processing.
Speed Your Production Process
Accelerate your survey workflows with the productivity tools in Virtual Surveyor (VS). The software produces the bulk of the output. You only need to review, remove, and add some points or breaklines to complete the job.
You will see that Virtual Surveyor has a simple user interface. There are not a ton of overbearing tools within the software. Along the left side you will find your project data. As you create layers for points, breaklines, topo, etc., they will show up in this dialog box. See Figure 1.
Analyze the virtual environment and draw points, point grids, lines, and polygons where you would measure them if you were in the field. Fly around and look at different angles to make sure your survey is accurate.
You can add descriptions to your points as you pick them on screen. And if your Civil 3D is set up to run the automated linework, creating these points and importing into Civil 3D is an extremely streamlined workflow.
Have a big field and want to create a grid of points? VS allows you to create a polygon around an area and perform multiple functions such as creating a grid or even removing vegetation. To create the polygon, simply choose the polygon tool from the ribbon, then draw your area of interest on the screen (Figure 3). Once that is drawn in, select your option and grid sizing from the ribbon and your points will be created. This is a great way to minimize the amount of data you bring into Civil 3D.
One more tool in the survey workflow I use a lot is the modify terrain tool. One of the biggest pains with UAV data is to remove things such as vegetation, buildings, and cars. There are plenty of classification tools out there and we even have tools in Civil 3D and InfraWorks that help a little, but with the Modify Terrain tool in VS, the process has become very simple.
Figure 4 is a photo before the modification.
To perform the task, draw a polygon around the area you wish to modify and select the Modify Terrain command. That’s it! The terrain is adjusted based on the 3D Polygon you just created, and just like that the problem areas have been removed. But don’t worry, if you don’t like the results, you can either remove the data from the project info along the left, or modify the results in several simple ways. This makes quick work of cleaning up the terrain on even the largest projects!
Figure 5 is a photo after the modification.
There are plenty of easy-to-use analysis tools within VS. From the measurement tools you can quickly check slope, distance, and height of objects. From the terrain analysis tools, you can quickly display your contours in multiple different intervals, modify terrain and slope colors, and also turn on slope arrows showing the direction of flow. In Figure 6, you can see the contour turns along with the slope arrows. This is a good example of how detailed and accurate drone data can be, and just how easy it is to consume that data without bogging down your machine.
There are several additional methods of terrain analysis. You can create a quick profile, view line of sight from several vocal points, and create a viewshed of anywhere on site.
You don't need a powerful computer to make a big impression. Virtual Surveyor runs on a simple laptop. Your data is displayed fluently and you have full control over all movements you want to make.
Understanding a problem is one thing, but communicating it to other people is quite another. Virtual Surveyor has a set of tools that allow you to present your work as video or interactive presentations.
Share Your Data Easily
Do you need to deliver your work to a customer or share it with a colleague? VS offers a free version that allows you to bring your virtual site to the desk of your clients and customers.
Bringing It All Together
At the end of the day, we still need a useable CAD file of the existing conditions. Whether it is a boundary and topo drawing, an ALTA, or just a surface within Civil 3D, we still need that data. It has to be consumable by the whole team of designers, drafters, and engineers.
Virtual Surveyor makes this process extremely simple. I see a couple different workflows here.
- Create points in VS, export to CSV, and import into Civil 3D for automated linework.
- Create breaklines in VS, export to DXF, and create basemap from there.
Either way, VS gives you multiple options to create your CAD file. An Export panel on the Home tab allows you to export data in multiple formats. To export points, simply choose the format (DXF, CSV), choose the property, and select Export Survey (Figure 7).
You can then export any linework you have created in VS. You can export linework as a DXF file or a Shapefile.
The final export option allows you to export the terrain you created in VS. VS allows you to triangulate and contour your data as you create it, and then export your final surface if you’d like. You could also just export points and breaklines and create that surface inside Civil 3D. See Figure 8.
Being able to use all this awesome data is key. Flying a site and having a cool point cloud is just the beginning, but there has long been a gap between drone data collection and what most surveyors and engineers still need in Civil 3D. With Virtual Surveyor we have now been able to bridge that gap and make a final deliverable that can be consumed from one aspect of the project to the next.