The new Terrain Model (i.e. : TM) extraction functionality allows user to create a Terrain Model element from the data stored in one or more Scalable Terrain Model (i.e. : STM) element. The TM element is created from the full resolution data available in the STMs. The goal of this function is to improve the interoperability between the STM and the TM element by allowing users to perform analysis (e.g. : watershed, line of sight, volume calculation) or other functionalities available on a TM element.
Note that since the data of a TM element is kept in the computer memory the area that can be extracted is limited by the number of STM’s terrain data available in that area. If the area contains too much terrain data a warning will be displayed with the approximate number of times the area is too big.
Finally the Extract a TM from STM functionality is different than the Export STM to TM functionality since with the later all the data in one sub-resolution of STM is used to create the TM, possibly leading to some loss of precision (i.e. : filtered full resolution data).
Here is a video showing how the extract functionality works.