PHOTOMOD DTM — module of Digital Terrain Model (DTM) creation
The PHOTOMOD DTM module creates and edits the digital terrain model (DTM). The module supports any type of digital terrain model — pickets,
breaklines, TIN, DEM, contour lines, etc. DTMs may be edited in either mono or stereo mode. A special 3D-window is used to view and analyze DTMs
from different angles.
TIN (Triangulated Irregular Network) is the basic DTM type in PHOTOMOD. It presents a piecewise-linear interpolation model of surface. TIN may be converted
into DEM (Digital Elevation Model). TIN is formed from a set of basic point objects (pickets, which are used as nodes in the triangulation network) and
breaklines (3D vector lines drawn along lengthy relief forms, such as mountain ranges and thalwegs). When editing basic vectors, TIN is rebuilt dynamically.
PHOTOMOD DTM has a powerful set of tools for creating, editing, filtering and checking vector objects*. External vector data can also be imported for use.
Pickets (3D vector points) can be created manually or automatically over the regular grid, as well as in pathway mode.
DEM can be created either from TIN or a set of 3D pickets. DEM can be imported from several popular formats, and its size is unllimited. The toolset also
provides the ability to cut DEM fragments, merge and filter DEMs, or transform to different coordinate systems.
Contour lines can be created from TIN or DEM. PHOTOMOD 5.0 builds two types of contour lines: “quasicontours”, which are created and updated automatically
during TIN editing, and the final “smooth” contour lines of topographic quality. All operations specific to contour editing can be applied to smooth contours.
* PHOTOMOD DTM creates vector objects without the classifier. PHOTOMOD StereoDraw module is needed to attach
vector objects to the classifier.