Presagis .flt (OPENFLIGHT) Reader/Writer

Licensing options for this format begin with FME Desktop Professional Edition.

The OpenFlight Reader/Writer enables FME to read and write OpenFlight (.flt) files.

The OpenFlight format was originally developed in 1985 by Software Systems as an interchange format between different image generators used primarily in flight simulation.

The OpenFlight (flt) standard has gone through many revisions and is now managed by Presagis. OpenFlight is widely used as an interchange format between different 3D modeling, visual simulation, and rendering applications For more information on the OpenFlight format, go to

Reader Overview

The OpenFlight Reader produces FME features for geometry data from OpenFlight files.

The hierarchy of geometries from the OpenFlight files will be preserved. For example, geometries under a group node will become geometries within an fme_aggregate.

Writer Overview

Note: The OpenFlight writer implements a subset of the OpenFlight format version 16.1 and can write to versions 15.7 or 15.8.

Characteristics of the OpenFlight writer:

  • IFMESurface and IFMEMesh geometry are converted into triangle meshes.
  • The OpenFlight files are written with z up coordinates in meters.
  • The OpenFlight writer produces an .flt file for each Feature Type sent to the writer.
  • Texture files are written to a common folder and referenced by OpenFlight models for each instance of a OpenFlight writer.
  • The companion OpenFlight texture attribute file (.attr) is written alongside texture image files.
  • Any old files in the output folder are overwritten with the new files with the same name. If the output files cannot be written, the translation fails.
  • The OpenFlight Writer supports feature type fanout, levels of detail, and master file creation.