Using vectors to generate a digital elevation model

OrthoEngine can calculate the elevations from vector layers to generate a raster digital elevation model (DEM), which is saved as a PCIDSK file (.pix). OrthoEngine uses raster DEMs to orthorectify images. If your elevation data is stored as vectors such as contours, points, TIN, or even a text file containing coordinates, you can convert them into a raster DEM as long as the vectors are in any of the supported formats.

Note: You can combine vectors from different layers and files to generate a DEM.

Vector layers can contain:

Points: A point is a single coordinate (x, y, and z).
Lines: A line is a start and end coordinate with points in between to define the shape.
Polygons: A polygon is a line with the same start and end coordinate forming an area with numerous points along the line to define its size and shape.
Contours: A contour is a line formed by a set of points representing the same value of a selected attribute. Contours are usually used to represent connecting points on the ground with the same elevation.
TIN: A Triangulated Irregular Network (TIN) is a digital model of adjoining triangles formed from points selected on the terrain to represent an accurate model of the surface. The TIN model can contain coordinates and other geographical data.

In the File box, type the path of a vector file or click Select to select a file.
Under Vector layers available, click the layers of your choice and click the arrow.
To add vectors from other files, repeat step 1 and step 2.
In the Data type list, select the type of vector in the layer. Click:
- Points for a layer containing only points or one vertex.
- Contours for a layer of vector lines with elevation values.
- 3D Lines for a layer with three-dimensional (3-D) breaklines or features.
- Valleys (2D) for a layer of two-dimensional (2-D) breaklines without elevation values that is used to represent valleys.
- Ridges (2D) for a layer of 2-D breaklines without elevation values that is used to represent ridges.
- Cliffs (2D) for a layer of 2-D breaklines representing cliffs, which are treated as a local discontinuity. The interpolated elevations from either side of the breaklines may be radically different.
- TIN for a layer of 3-D breaklines using the TIN model. The 2-D layers provide additional constraints for the interpolation of the source elevations. In particular, a valley vector indicates a local minimum, a ridge vector indicates a local maximum, and a cliff vector indicates a discontinuity in the DEM.
In the Elevation source list, click where the elevation value is stored. The elevation values can be stored in several ways such as the z coordinate of the feature or in an attribute field.
Click OK.