Blue Marble Monthly: Point Cloud Processing, 3D Fly-Throughs, and Vector Extraction, oh my!

Satellite imagery

Product News, User Stories, Events, and a Chance to Win a Copy of Global Mapper Every Month

The release of version 20 of Global Mapper is still generating a lot of buzz, and that is especially true of the new LiDAR Module tools. In this month’s newsletter, we take a moment to consider some of the highlights of this add-on to Global Mapper in a Top Five list. As the end of the year approaches, our focus now turns to Geographic Calculator 2019, which is currently in its beta testing phase. If everything goes according to plan, the release version should be available within a few weeks. Check your inbox for an official announcement. As a teaser, we preview some of the highlights of the Calculator release.

Also this month, we demonstrate how easy it is to create a 3D fly-through in Global Mapper, we revisit the software’s raster-to-vector capability using the new Color Picker tool, and as always, we offer a free copy of Global Mapper in the Where in the World Geo-Challenge.

PRODUCT NEWS  |  Top 5 Features of the LiDAR Module

It has been five years since the Global Mapper LiDAR Module was introduced. The first version offered some basic tools for streamlined LiDAR editing and filtering but more importantly, it provided a platform on which increasingly advanced point cloud processing capabilities would subsequently be added. In a recent blog post, we highlighted five of the most important LiDAR Module tools.

 

PROJECTIONS  |  Creating a 3D Fly-Through in Five Steps

Data visualization is a fundamental component of any functional GIS and in today’s geospatial world where 3D data has become the norm, 3D visualization is essential. Global Mapper’s fly-through capability provides a simple but powerful means to dynamically explore and examine the 3D environment and, as is typical with Global Mapper, it involves just a handful of steps. Five to be exact.

 

DID YOU KNOW | Vector Extraction from a Raster layer

Did you know that Global Mapper includes a tool for automatically vectorizing features from a raster layer? Thought not. While it doesn’t get the same attention as some of the other powerful analysis tools, it is, in its own right, an invaluable component of the software. With the introduction of the Color Picker tool in version 20, this vectorization capability has become even more straightforward. Check out this short video to see for yourself.

 

COMING SOON  |  Geographic Calculator 2019

While it is risky to introduce the highlights of a software release while it is still in development, we are confident the new functionality currently being beta tested in Geographic Calculator 2019 will be available in the final release in a few weeks. Among the most important upgrades are:

  • Optimized architecture for Windows 10 environment
  • A new capability to copy and paste blocks of data grid values into spreadsheets
  • Updated icons and graphics for jobs and tools
  • A new Angular Unit Converter tool
  • Updated Seismic Survey Conversion Job with enhanced P1/11 format support and additional SEG-Y format coordinate scalar handling
  • And much more

Look out for a release announcement in your inbox shortly.

 

Where in the World Geo-Challenge

You may have noticed that the Geo-Challenge questions have been getting steadily more difficult over recent months. This has not deterred an increasing number of you from proving your geographic prowess and correctly identifying all five locations. Among those who seemingly had no problems with October’s challenge was Ian Rath of Arcadis Australia Pacific. Ian will shortly be receiving a copy of Global Mapper for his efforts.

To find out how you did on last month’s challenge, check out the answers here.

If you’re up for another try, click the link below to test your geographic knowledge in the November edition. Good luck!

 

See complete terms and conditions here.

EVENTS  |  Upcoming Conferences

At the time of writing, two Blue Marble teams are on the road, spreading the word about our products in Indianapolis and Las Vegas. Next week we have a crew in London at The Commercial UAV Show and another in Halifax, Nova Scotia at the Geomatics Atlantic Conference. If you’re going to either of these events, stop by and say hello.

As anticipated, the Orlando Global Mapper training class in December is full but you can add your name to a waiting list to see if a slot becomes available. Looking forward to 2019, we are in the process of finalizing the training calendar. No promises, but if you would like to see a training class in your neck of the woods, let us know by emailing training@bluemarble.com.

Where Blue Marble Will Be Next

Visit with Blue Marble at the following events:

Geomatics Atlantic
Halifax, Nova Scotia, Canada | November 14 – 16

The Commercial UAV Show
London, UK | November 14 – 15

I/ITSEC
Orlando, FL | November 26 – 30

Global Mapper and LiDAR Module Training
Orlando, FL | December 4 – 6

Creating a 3D Fly-Through in Global Mapper in Five Easy Steps

Let’s begin with a poll. With a show of hands, how many of you currently work with some sort of 3D data in Global Mapper?* One, two, three, four… OK, I think I can safely conclude that everyone’s hand is raised, just as I thought. We are currently at a significant epoch in the history of mapping. Traditional cartographic renderings consider the Earth from a two-dimensional, birds-eye perspective but that is rapidly changing. Our world is a 3D world and the technologies that we use to visualize, analyze, and distributize** our geospatial data are increasingly taking the additional dimension into consideration.

Case in point is Global Mapper’s ingenious fly-through recording capability. What better way to show your client the scope of your engineering project, or to share the archeological model created using the Pixels-to-Points tool, or to simply soar over mountains and valleys unencumbered with the constraints of gravity, feeling the wind in your face as you glide… OK settle down. Back on task.

As is typical with Global Mapper, the fly-through recording functionality is remarkably straightforward. Draw a line defining the flight path, enter the flight parameters, open the 3D View, click the Play button and you’re on your way (with seatbelts fastened and tray tables in their upright and locked position, of course). Alternatively, if you have a prerecorded track file, such as one that was created by a drone, you can use that as the flight line. All of the flight parameters such as speed, height, etc., will be automatically assigned.

Let’s take a look at an actual example.


1. Load a 3D data layer in Global Mapper

In this scenario, we’ll use a 3D mesh created in the Pixels-to-Points tool. Frequent viewers of Global Mapper video presentations or training class attendees will already be familiar with the data in question ̶ ­the famous Brazilian landfill.


Drawing a flight path in Global Mapper
Drawing the flight path using the Digitizer’s Line tool

2. Draw the flight path

Before putting pen to paper (or digitizer to screen, to be more precise), we will need to consider what form our flight will take. There are three alternatives: Straight Ahead, in which the view will look in the direction of the flight (a cockpit view, if you like); Fixed Direction, in which the view will always be on a specified bearing or azimuth; or Fixed Point, in which the view will always be focused on a target point in three-dimensional space. Because we will be using the latter, we will create a line that encircles the focus point.


3. Set the flight parameters

With the newly created line selected on the map, we click the Create 3D Fly-through button (hint: it looks like an airplane, you can’t miss it). If you haven’t seen it before, the dialog box includes a table listing the XY coordinates of each vertex in the line along with a number of additional columns that will be automatically filled in after we apply the necessary settings.

Setting flight parameters in Global Mapper
Setting the flight parameters including focal target, altitude, and speed

As previously noted, we’re going to use the Fixed Point option, which requires us to enter the focal target, a process made easy using the Select from Map button. Because we want the perspective to be looking down rather than horizontally, we establish a target Z value corresponding with ground elevation or a little below, let’s say 550 meters.

Elevation Mode in this case will be Absolute, meaning that our flight will maintain a specific altitude. The alternative, Relative to Ground, will result in the simulated flight rising and falling while maintaining a consistent height about the surface (the captain apologizes for the turbulence). For our landfill flight, we will be cruising at a consistent altitude of 650 meters.

Finally, we need to decide how fast we want to fly. This can be established by either setting the duration of the flight or by entering an actual meters-per-second value. Setting one of these variables will automatically change the other. Our circuit of the landfill will take 40 seconds.

Clicking the Generate Fly-through Data button will populate the aforementioned table with per-vertex flight details and double-clicking on any line in the table will offer the option of editing the settings for that segment. After clicking the OK button, we’re ready to take to the air.


Viewing the flight playback in 2D and 3D
Viewing the flight playback in the 2D and 3D Views

4. Play the fly-through

Now for the fun part. In the 3D View, a collection of buttons controls the preview, playback, and editing of the flight. Click Play and away we go. In the corresponding 2D view, we can monitor our progress and heading along the flight line. Should we need to make any changes, there’s an identical airplane button in the 3D View, which opens the same dialog box that we used to create our flight.


5. Export the video

Finally, we click the button that resembles a vintage movie camera to save a video file in either MPEG-4 or AVI format with options for defining the resolution and frame rate. The video can then be posted to our favorite movie sharing site or sent directly to a client.

Wasn’t that easy? Time to try it for yourself.

*If you actually did raise your hand in response to reading this question you might want to explain to your office colleagues what you were doing

**Not a real word

Vector Extraction from a Raster Image in Global Mapper

 

In this example of extracting vectors from a raster layer in Global Mapper, we will automatically create polygons outlining lakes from an aerial image.

Here are the steps to follow to extract a vector from a raster layer:

  1. From the Layer menu, click Create Area Features from Equal Values…
  2. Name the target layer and choose the option to extract Only Selected Color(s)
  3. Choose Select Color from Map and click on a location representing the required color
  4. Apply a Color Fuzziness value and define the extent of the extraction process
  5. Use the Digitizer to remove unwanted polygons

The extracted polygons can be exported in any supported vector file format

Top 5 Tools and Functions of the Global Mapper LiDAR Module

In anticipation of the increasing availability and use of LiDAR and other point cloud datasets, the LiDAR Module, an add-on to Global Mapper, was first introduced in version 15 of the software. Over the last five years, this popular component has rapidly evolved and offers an array of powerful tools.

In this blog entry, we highlight the top five most important tools and functions in the LiDAR Module, including extracting vector features, processing UAV-collected images into point clouds, filtering LiDAR data, and generating 3D meshes or models.


Pixels-to-Points Tool in Global Mapper
3D Point cloud of a barn viewed created with the Pixels-to-Points tool

1. Pixels-to-Points

The newest addition to the LiDAR Module, Pixels-to-Points is a tool for creating a high-density point cloud, orthoimage, and 3D meshe from overlapping images, especially those captured using a drone

Based on the principles of photogrammetry, the Pixels-to-Points process identifies objects in multiple images and from multiple perspectives to generate a 3D point cloud. As a by-product of the point-generation process, the tool can also create an orthoimage by gridding the RGB values in each point, as well a 3D mesh, complete with photorealistic textures.

Pixels-to-Points offers photogrammetric point cloud creation that is both affordable and straightforward, and is increasingly used as an alternative to traditional LiDAR collection.


Auto Classification of LiDAr points
Buildings and trees identified and reclassified in a LiDAR layer

2) Auto Point Reclassification

The LiDAR Module’s automatic reclassification tools can accurately identify points representing ground, vegetation, buildings, and utility cables.

Algorithms in the LiDAR Module analyze the geometric properties and characteristics of point clouds to quickly classify these features. This process is commonly used to identify, classify, and filter ground points when creating a Digital Terrain Model (DTM), or as a first step in the process of isolating specific feature types when extracting vector features, such as buildings or trees, from a point cloud.


Feature Extraction using the Global Mapper LiDAR Module
Vector lines representing above-ground power cables extracted from LiDAR data

3) Feature Extraction

The Feature Extraction tool is used to create vector objects from appropriately classified points.

Based on a series of customizable settings, points representing buildings, trees, and utility cables are analyzed and automatically delineated as a series of 3D vector objects or, in the case of buildings, as a 3D mesh.

Feature extraction is particularly useful for creating building footprints, defining roof structures, powerlines, and other 3D features from classified LiDAR data.


Digitizing the edge of a curb using the Global Mapper LiDAR Module
Digitizing the edge of a curb using the perpendicular profile function

4) Custom Feature Extraction

Custom Feature Extraction is a function for delineating atypical 3D features from point cloud data.

This function allows for the creation of accurate 3D line or area features by defining control vertices in a sequential series of perpendicular path profile views. Examples of using Custom Feature Extraction might be for defining road curbs, pipelines, or drainage ditches,


3D Mesh created using the Global Mapper LiDAR Module
3D Mesh of a suburban neighborhood created from selected points in a point cloud

5) Mesh Creation from LiDAR Points

Mesh Creation is a function that uses a selected group of points to create a 3D vector object complete with photorealistic colors or textures.

The LiDAR Module offers the ability to create a mesh or model using the 3D geometry and colors of a selected group of points. When viewed in 3D, this model displays as a multifaceted photo-realistic 3D representation of the corresponding feature.

For information about all of the features that the LiDAR Module has to offer, visit our website here.

Where in the World Geo-Challenge – November 2018

View the form at Google Forms >

Where in the World October 2018 Answers

How Well Did You Do?

Name the body of water – Gulf of Carpentaria

 

 

 

 

 

 

 

 

 

 

 

Name the capital city – Dakar

 

 

 

 

 

 

 

 

 

 

 

Name the river – Paraná River

Parana River

 

 

 

 

 

 

 

 

 

 

 

Name the island – Severny Island

Severny Island

 

 

 

 

 

 

 

 

 

 

 

Name the country – Albania

Albania