More info here
MergeSmoothing is a windows program that will read an FBX file and generate smoothing groups based on the normals of the mesh. It can read in earlier FBX versions and will output a 2013 FBX file. UDK wants smoothing groups and it wants version 2013 files. If both conditions are not met it will generate a warning message.
original ut3 characters translated for use with lightwaves fbx exporter.
The Doom3 scripts for truespace 7.61 will read and write idtech 4 md5mesh and md5anim files.
Some notes for working with trueSpace and the UDK. Exporting T3D, FBX, FBX for matinee, T3D terrains, PSK and PSA files. When complete will be a recipe for transfering a complete tS scene into a UDK level.
Unreal T3D file format specs no longer available from original source
UDK Scaleform samples converted from Flash CS4 to version CS3