Tutorials CivilCraft help Walkthroughs
Export as-built data for GIS
Hand survey points, contours, alignments, pads, pipes and structures to a city or county GIS department as shapefiles, GeoPackage or GeoJSON, in grid coordinates of the project's coordinate system.
Written for CivilCraft 0.3. The same help is inside the app: press F1.
Many cities and counties ask for as-built data in a GIS format when a project closes: where the pipes and structures went, final grades, the road centerline. GIS › Export writes what CivilCraft holds as GIS layers, one per kind of object.
Before you export
- Set the project's coordinate system in Coordinates. A GIS department needs to know where the numbers are; without a system the files carry the project's own numbers and name none.
- Check the surface, alignments, pads and pipe network the way you want them delivered.
- Ask the department which format and which coordinate system they want. Many still ask for shapefiles in the local state plane zone; newer systems take GeoPackage.
Export
- Click Export in the GIS group.
- Under What, tick the kinds to send. Each shows how many features it has; kinds with nothing yet are grayed out.
- Under As, pick the format.
- Read the notes about coordinates and units, then click the download button. The status line says what went in, and any field names that were shortened.
The dialog also holds the elevation grid export (Surface as a GeoTIFF elevation grid); see Elevation grids and LiDAR.
What each kind holds
| Kind | Shape | Fields |
|---|---|---|
| Survey points | Points with elevation | P point number, N northing, E easting, Z elevation, D description |
| Contours of existing ground, of the graded surface | Lines at their elevation | ELEV |
| Breaklines | Lines with elevations | NAME |
| Surface boundary | Polygon (the drawn boundary, else the surface's edge) | NAME |
| Alignments | Centerlines | NAME, LENGTH, STA_START, STA_END (stations as plain numbers) |
| Pads | Polygons at the pad elevation | NAME, ELEV, AREA |
| Daylight lines | Lines with elevations (pads and corridors) | NAME |
| Corridor feature lines | Lines with elevations: center, edges of pavement, shoulders | NAME, CODE (CL, EOP_L, EOP_R, SH_L, SH_R) |
| Pipes | Lines from the upper to the lower invert | NAME, FROM, TO, DIA, DIA_UNIT, INV_UP, INV_DN, SLOPE (percent), LENGTH, NETWORK |
| Structures | Points at the rim | NAME, RIM, INVERT (the lowest pipe invert there), SUMP, DIA, DIA_UNIT |
| Each GIS layer | As imported | Its own fields |
Lengths, stations and elevations are in the project's units (US survey feet or metres). Pipe and structure diameters are in inches for feet projects and millimetres for metre projects; DIA_UNIT says which.
The formats
- Shapefile: one
.zipwith a shapefile per kind (.shp,.shx,.dbf), a.cpgsaying the text is UTF-8, and a.prjnaming the coordinate system. Shapes with elevations are written as the shapefile's Z types. Field names longer than 10 characters are shortened, as the format requires, and the status line lists them. - GeoPackage: one
.gpkgfile with a table per kind, the coordinate system stored with its EPSG code. One file instead of many, long field names kept. - GeoJSON: one file of latitude and longitude (the GeoJSON standard allows nothing else) with every feature carrying a
kindproperty (pipes,structures, …) so the receiver can split them. Heights are converted to metres, as the standard asks; they stay on your project's vertical datum (CivilCraft has no geoid model). A project without a coordinate system cannot export GeoJSON, and the dialog says why.
Grid, not ground
GIS departments keep their data in grid coordinates of a coordinate system. If your project uses ground or local coordinates (set in Coordinates), every coordinate is converted back to grid on the way out: the numbers in the files differ from the plan's by your scale factor (and rotation, for a local system). The point fields N and E hold the grid values too. The dialog reminds you.
What was checked
- Every file written was read back by GDAL, the library most GIS programs use to read these files: each shape, elevation and attribute, the feature counts, and the coordinate system as its EPSG code (
.prjand GeoPackage). Our own readers read them back the same. - GeoJSON files follow RFC 7946: longitude before latitude, no
crsmember, outer rings counter-clockwise and holes clockwise; positions matched PROJ to 2 mm. - A ground-coordinate project was exported and every point checked against its grid coordinates.
- Nothing here has been opened in other GIS programs yet. Check the first delivery with the department before relying on it.