Project items are the building blocks of the Virtual Surveyor software and represent types of data that are used in the software. 

Project items are listed and grouped by layers in the project view where they can be selected. Most project items are displayed in the viewport (except location) from where they can also be selected (except terrain modifier and terrain offset).

Every item has a descriptor and optionally a number which can be updated in the Structure group of the Home tab.

The list below gives an overview of the different project items that are available with Virtual Surveyor.

Project itemDescriptionSymbol
PointA geometry that has a location in geographic space, but that has no extent. A point is represented through a symbol, color and size. You draw points to describe the topography at bare-earth or to capture specific features like a manhole.
Multi-pointA set of Points. Multi-point items are typically created through a grid operation like Q-Points or Low-pass points. Multi-point items allow to easily manage very large sets of points as a single item.
PolylineA geometry that consists of line segments that connect a series of geographic coordinates. A polyline is displayed with a color and a width. You draw breaklines to capture sudden changes in slopes like banks in quarries, road embankments, ...
BoundaryA geometry that is a closed polyline. A boundary is displayed with a color and a width and doesn't have a fill. A boundary confines a work area and is used as input in many operations like gridding, triangulation, terrain export, ...
SurfaceA set of triangles that is used to describe the topography. Surfaces are displayed as triangles or contour lines and can contain holes. Surfaces are used as input for a volume calculation, a terrain modification or as a deliverable for your customer.
VolumeRepresents a certain quantity of material or dirt. Volume items are created by comparing a terrain with another terrain or surface. It is displayed in 2 colors representing a cut volume on one hand and a fill volume on the other hand.
Image terrainTypically the orthophoto from your drone photogrammetry. Image terrains can also be a topographic map (thematic colors) or cadastral map (black/white colors). Image terrains are draped over the elevation terrain.
Elevation terrainThe DSM (or DTM) from your drone photogrammetry. Also point cloud files from LiDAR drones are imported as elevation terrains. The elevation terrain is shown as a hillshade or augmented with the image terrain or other terrain lenses.
WaterA plane at a certain elevation that is used to represent water. Water items can be clipped or intersected with the terrain. Water items are used to remove noise over water bodies and to calculate the fill volume for basins.
Terrain modifierA terrain modifier is created from an input surface and replaces the elevation terrain completely. You typically use a terrain modifier to remove machines and conveyors before calculating a volume difference between 2 terrains. 
Terrain offsetA terrain offset is created from an input boundary and changes the elevation with a certain value. The terrain offset is typically used when you have ellipsoidal elevation while you need mean sea level or a local elevation datum.
LocationA view position from which you observe your drone data. You typically find yourself at a certain geographic position, viewing the terrain at a certain angle with respect to the horizon and north.
MeasurementCaptures the specific characteristics of a certain part of your topography. A measurement is used to show the height for banks or structures or the steepness of slopes.