This is documentation of an archived release.
For documentation on the current version, please check Knowledge Base.

Glossary Technical Concepts

This page is a glossary describing some basic concepts of the 3DM Viewer and 3DM Viewer SDK.


A Bookmark is a utility for Named Users that allows them to store a Workspace for later reference. By default, this is a private utility, available from the Bookmark sidebar of the Viewer.

Bookmarks can also be opened by anyone with the Bookmark's URL :

  • All Named Users can open a Bookmark, providing they have access to the same Resources used in it.
  • Anyone else can open a Bookmark that is made public, providing the Organisation has enough Guest Users left.


A Coordinate represents an exact geographical location in a specific CRS.

By default, all data returned by the SDK is expressed in WGS84, EPSG:4326 To change the CRS of data returned by the SDK, please provide the Constants.STARTUP_CRS option at Viewer startup.

Coordinate Reference System

A CRS or Coordinate Reference System is a system used to interpret locations of features with the use of their coordinates. For more information on the use of Coordinate Reference Systems in Orbit, please visit Coordinate Reference Systems.

Spatial objects provided to the Viewer must always be accompanied by a CRS code.

Spatial objects that are returned by the SDK are expressed in WGS84 (EPSG code 4326) by default. You can change this by passing a Startup Option to the Viewer constructor, instructing it to use a different CRS.


Coverage is an overall term to point out vector data which consists of the Footprints, the Envelope, and the Field of Views of a run.

Field Of View

A Field Of View is the representation of the position, direction or bounds of a View on the Reference Map.
Field-Of-Views are provided by the SDK as MapObjects.


A Footprint is the representation of a visible Resource on the Reference Map. Footprints are useful to indicate data availability. Footprints can be Photo Positions, a Trajectory or an Envelope.

Footprints are provided by the SDK as MapObjects.


Global state (focus, mouse hover).


When you launch the SDK, you need to log in to a service that will provide the data. The SDK supports both cloud-based and on-premise content. There are 3 ways to login :

  1. Login to 3D Mapping Cloud as Named User: Requires User and Password.
  2. Login to 3DM Publisher: Requires Publisher Url, User, and Password. Then choose a Publication.
  3. Use a token to get access to a 3D Mapping Cloud Publication as Guest User: Requires a Publication or Bookmark token.

It is possible to pre-set the login credentials or to use them to log in automatically.

  • The preset requires the user to confirm and allows us to pick another login option.
  • Auto-Login requires no user interaction and disables the option to use another login option.

Note: For security reasons, we do not allow the SDK Developer to preset a 3DM Cloud Named User Login.


Visualisation of Data

To represent objects to be rendered, we decided on introducing a self-describing type called a MapObject.

  • It describes its own spatial component (point, line, area)
  • It describes its own legend component (line color, etc…)

Currently we have 4 types of MapObjects that are to be rendered in their own layer.

  • Field-of-views : visualisation of view states.
  • Measurements : Visualisation of measurements.
  • Globals : Visualisation of global state (focus, mouse hover).
  • Footprints : Visualisation of where resources have data available.

By using MapObjects, we move the complexity of representing Viewer data out of your code and into the Viewer SDK itself. Let us worry about presentation.


A Measurement can be a point, line or area you measure. When creating a Measurement, you are always doing so in a specific mode. The Measurement mode defines what you are measuring.

When making a Measurement, you are making registrations. Depending on the mode, the required number of measurements can be fixed, or open-ended. An open-ended measurement mode requires the user to close the Measurement manually (usually by double-clicking on the last measurement).

Pan Angle

The viewing direction of a view in the horizontal plane with 0 degrees indicating north and 90 degrees indicating the east. Pan is similar to the concept of heading in navigation.


A Publication is a representation of Resources in the Viewer. A publication is the end product of the 3D Mapping Cloud or 3DM Publisher.


A Promise is an object instance that is a placeholder for a value that is not yet available. When the value is not yet available, a Promise is said to be 'pending'. When the value is available, the Promise is said to be 'resolved'. If a problem occurs the promise is said to be 'failed'.

The user of a Promise can attach listeners to the Promise to be notified when the Promise either resolves or fails.

Reference Map

The Reference Map is the 2D map, which is part of the Viewer. It shows you where Resources and Views are situated in the form of Footprints and Field of Views.

The Reference Map is the map on which you can get your bearings. It shows you where Resources and Views are situated.
The Viewer has an built-in reference map.
The Orbit 3dMapping Viewer SDK was created specifically to to enable any third-party viewer to be used as a reference map.


A resource is a dataset that can be opened in the Viewer. A resource can be one of the following types: Mobile Mapping run, Oblique project, UAS run, vector data, point cloud, textured mesh.


A Signal can be best described as an event emitter. Signals are provided throughout the SDK to cover different use-cases where your integration will want to be notified of certain events.

Signals start with “on” by convention (for example “onFootprintsChanged”).

Start-Up Options

A Start-Up Option is a named value that can be provided on viewer startup. It can be used to affect some inner workings of the Viewer.

One example of such an option is the “CRS” option. This setting can be used to provide the CRS to be used by the SDK when returning spatial data. The full list of options can be found in the reference documentation (startup options have a STARTUP_ prefix).

Tilt Angle

The viewing direction of a view in the vertical plane parallel to the viewing direction. Zero degrees indicates the view is looking at the horizon and 90 degrees indicates the view is looking up. Tilt is similar to pitch in aviation.


There are 3 types of users, all automatically handled by the SDK (see Log in)


A View is a single interactive component of the Viewer Workspace that visualizes the visible Resources, in some way or form.


The Viewer is the framework in which a publication is made and resources are represented.


The central Viewer component is named Viewer3DM.


A Workspace defines a list of Resources and how they are presented by the Viewer. A Workspace uses one or more View components to display the Resources. A Workspace also includes a range of settings and parameters that help build up the full state of the Viewer.

Publications and Bookmarks use a Workspace to store the Viewer state. Bookmarks let you share a Workspace informally. Publications add permissions and an extra layer of configuration to create a more formal presentation of the data and viewing experience.

Last modified:: 2023/05/12 16:31