October 12, 2021
Creating a 3D Fly-Through in Global Mapper
The 3D Viewer tool in Global Mapper makes it easy to view, zoom, and pan through data in three-dimensional space. Easily accessed from the Viewer toolbar, the 3D Viewer opens a floating pane that can be moved, resized, and even docked within the larger Global Mapper window. By default, the 3D Viewer displays all loaded data including digital elevation models, point clouds, and vector features. In addition to manually zooming and panning the data, a simulated fly-through visualization can be set up and recorded to a video file to show off and share views of your 3D data.
Data Setup
Before creating and recording a fly-through, the data loaded in the workspace and 3D Viewer can be styled to optimize the display of the data. In the 3D View Properties, accessed through Configuration, the vertical scale, lighting, and display of features can be altered.
For this example, terrain data is loaded for Manhattan, New York. The ground in this area is relatively flat so vector layers containing buildings and park features are loaded to provide more detail. To display the buildings as solid-looking entities, they are extruded from the displayed terrain surface. Choosing to display the features at the roof height elevation and enabling the option to Extrude 3D Vector Features in the 3D Viewer Configuration options, creates a more realistic representation of the city skyline.
3D Labels
To add some additional information and meaning to the vector features shown on the map, 3D labels are enabled by creating a label layer for the vector features. The use of a dedicated label layer allows the labels to be displayed, styled, and edited independently of the polygons from which they are derived.
In addition to selecting the font, size, and color for label features, text labels can be displayed in 3D in one of two ways: as flattened text, superimposed on the vector features they label, or as billboard features, which stand up and dynamically rotate to be easily read by the viewer. In this example, the billboard-style is chosen to label the parks of New York City before creating a fly-through.
Creating a Fly-Through Path
In order to share data with customers or colleagues who may not have access to a GIS program, a recorded fly-through provides the means to display the three-dimensional characteristics of the data.
To record a simulated flight, the flight path must first be created or imported into the workspace. A fly-through path can be created in Global Mapper by navigating through the 3D Viewer or applying additional settings to an existing line.
Walk-Mode and Fly-Mode
In the 3D Viewer, Walk-Mode and Fly-Mode provide two alternatives for navigating through the 3D environment from a first-person perspective, using keyboard and mouse controls to move through the data, much like video game navigation. When working in walk- or fly-mode click the record button in the 3D Viewer to record the path of navigation as a line. The action of moving within the 3D Viewer will be recorded as a 3D line, along with the needed camera parameters to recreate the flight path. This saved fly-through line can then be used to replay and export the flight recording.
From a Line Feature
To design a fly-through without using the live navigation tools in the 3D Viewer, the required parameters for a flight can be generated from a simple line feature. This could be a line digitized in Global Mapper or one imported from an external file. For this example, the line used is one copied from a layer of New York City streets. The connected line representing Broadway will be used as the horizontal starting point for the fly-through path.
From the Analysis toolbar, the button to Generate Fly-Through data is selected and general parameters can be entered to give the flight direction, speed, and elevation. Options in the Fly-Through Path Properties dialog include view direction, elevation, and flight duration. Entering values for these overall parameters and clicking to Generate Fly-Through Data will create a line with the needed parameters that can be used to play and record the flight.
Viewing a Fly-Through Simulation
In the toolbar of the 3D Viewer, there are buttons to play, pause, stop, and record a fly-through, as well as one to preview the individual frames of the flight.
Previewing a fly-through allows you to look at and edit the flight parameters along each vertex of the flight path. The path flown when playing the fly-through smoothly interpolates between these individual frames. Editing the flight through the preview option allows you to deviate from the single set of options used to generate the initial fly-through path in order to apply unique settings for each section of the flight. Altering the elevation and camera angles along the flight provides better views of the data and can result in a more interesting recorded video.
Playing the fly-through in the 3D Viewer and exporting the flight as a video file are very similar processes. Clicking play allows you to see the fly-through executed in the 3D Viewer, and clicking to Save Fly-Through prompts you for some additional video format information and then plays the flight in 3D as it is recorded.
