CAD Manager (DXF Import & Export)

Purpose: Exchange supported CAD geometry through DXF.

Before you start: CAD access, a suitable sample file, and a known coordinate reference system.

Expected result: Imported or exported geometry is checked in the intended receiving tool.

Use CAD Manager to import DXF drawings into a Mapplex project or export collected features as DXF files for engineering and drafting teams. Coordinate system selection is important: review the source CRS before importing and the target CRS before exporting.

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1. Opening the CAD Manager

1. Navigate to the Data & Sync tab.
2. Tap the CAD Manager button (amber gradient with DXF badge).
3. The CAD Manager modal opens with two tabs: Import DXF and Export DXF.

Subscription: CAD Manager is a Pro feature. Free-tier users see a lock icon on the button — tapping it opens the upgrade screen.

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2. Importing DXF Files

Step 1: Choose a DXF File

1. Tap the Choose DXF file button.
2. Select a .dxf file from your device (up to 20 MB). Select its .prj with it when it has one, or a ZIP holding both, such as a Mapplex CAD export: the coordinate system the .prj names is then offered From the file, to confirm rather than find.
3. The parser reads the file and displays:
   • Coordinate systems that fit it (Step 2)
   • Drawing units — what the file says its units are (Step 2)
   • Projected coordinates badge — the easting and northing ranges when the numbers are not longitude/latitude
   • Layer preview table — every CAD layer with its entity types (LINE, CIRCLE, LWPOLYLINE, etc.) and count

Step 2: Confirm the Drawing's Coordinate System

Mapplex offers thousands of supported coordinate systems from around the world. The coordinate system tells Mapplex where the drawing belongs on the earth.

1. If a matching PRJ file came with the drawing, review the system marked From the file.
2. Otherwise, choose the system supplied by the drawing's author. Search accepts its name or EPSG code, such as British National Grid or 2263.
3. Review suggestions near your project's data or recent map view. Best identifies the strongest location match, not a guarantee that it is the drawing's original system.
4. If several systems fit, ask the drawing's author rather than guessing. Other accepts a custom definition supplied by a specialist.
5. Read any accuracy warning before importing. An uncertain conversion can put features in the wrong place.

Tip: for a new project, zoom the map to the working area before importing. This helps order suggestions; it does not replace the source coordinate-system information.

Drawing units. A DXF says its insertion units ($INSUNITS). When they differ from the coordinate system's — a drawing in millimetres on a grid in metres — the numbers are converted (Convert them to the coordinate system's units, on by default). Feet and US survey feet are read as the same unit, as drawings rarely say which. A drawing that does not say its units is read in the system's units.

Tip: In a new project, open the Map and zoom to the project area before importing: the systems there are then suggested first. Once the project has data, its data guides the suggestions.

Step 3: Import

1. Review the preview table. The import button shows the exact number of convertible entities.
2. Tap Import Convertible CAD Entities (N).
3. A progress bar appears showing import status:
   • Checking permissions...
   • Converting DXF to GeoJSON...
   • Importing layer 1/3 — "Roads LineString" — 247 features
   • Saving features...
   • Generating form fields...
   • Done! — 892 features imported

Cancelling an Import

If a large file is taking too long, tap the Cancel button next to the progress bar. The import stops at the next checkpoint — any layers already fully saved remain in your project.

What Happens After Import

• Each CAD layer becomes a separate Mapplex layer, split by geometry type (e.g., "Roads LineString", "Buildings Polygon")
• Form fields are auto-generated from the imported attributes
• The map view is automatically refreshed to show the new data
• You are navigated back to the Data tab to see the new layers

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3. Exporting as DXF

Selecting What to Export

1. Switch to the Export DXF tab.
2. Choose a scope from the dropdown:
   • Entire Project — All features from all layers
   • Specific Layer — Only features from one layer

Generating the File

1. Select the target coordinate system for the exported DXF.
2. Tap Prepare DXF ZIP.
3. The system converts your GeoJSON features to DXF format:
   • Points → DXF POINT entities
   • Lines → DXF POLYLINE entities
   • Polygons → DXF closed POLYLINE entities; a hole is drawn as its own closed outline
   • Multi-geometries are expanded into individual entities
4. Complete the offered save or share action. Mapplex prepares a ZIP containing the drawing (.dxf), its matching coordinate-system file (.prj), and a short readme. Preparing the ZIP does not confirm that it reached your chosen destination.
5. Open the saved ZIP and extract it. Keep the DXF and PRJ together with matching filenames. Open the drawing in the receiving CAD/GIS application and confirm its position, units and expected geometry. Some applications require you to assign the supplied coordinate system explicitly.

This is a 2D geometry export. It does not carry your forms, attributes, attachments or related records. A polygon's hole is drawn as its own closed outline and an elevation is not written; review the export warning and use a suitable GIS format when those details are needed. Check the preservation limits.

If you cancel the save or share action, the handover has not finished. Prepare the ZIP again when you are ready to choose a destination.

Export Coordinate Systems

Choose the coordinate system the drawing is written in:

Option	When to Use
WGS 84 longitude/latitude (EPSG:4326)	The default: GPS longitude/latitude, GIS systems that expect decimal degrees
Made for where your data is	The national and local grids, and the UTM zone, for where the project's data is (else the area you last viewed on the Map); not continent-wide systems
Search	Any coordinate system by name or EPSG code
Other	A proj4 string or WKT for a local or organization-specific system

The ZIP holds the DXF and its .prj, which names the system. The .prj is written for Transverse Mercator and UTM, Lambert conformal conic, Mercator, Albers, Lambert azimuthal, Cassini and stereographic systems, and checked before it is used: read back, it must put every point where the system does. A system Mapplex cannot describe exactly in a .prj (for example Swiss oblique Mercator or Krovak), or one with no published shift to WGS 84, is refused and nothing is exported.

Confirm the receiving CAD team's expected coordinate system before sharing the export.

Compatibility

The exported DXF file is designed for common CAD/GIS tools that support DXF, including:

• AutoCAD
• Civil 3D
• BricsCAD
• QGIS
• MicroStation
• Any software supporting DXF R12/R14

Note: The PRJ describes the coordinate system; it does not guarantee that the receiving application has applied it. WGS84 drawings use longitude/latitude in degrees, not metres. Agree on a projected system when the recipient needs measurements in metres or feet. To import the drawing back into Mapplex, select the ZIP or the extracted DXF and matching PRJ together, then confirm the detected coordinate system.

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4. Supported DXF Entities

Import (DXF → GeoJSON)

DXF Entity	Converts To	Notes
POINT	Point	Direct coordinate mapping
LINE	LineString	2-vertex line
LWPOLYLINE	LineString or Polygon	Closed polylines become Polygons
POLYLINE	LineString or Polygon	Handles 2D vertex-based polylines
CIRCLE	Polygon	Approximated with 64 segments
ARC	LineString	Approximated with segments
ELLIPSE	Polygon	Approximated with segments
SPLINE	LineString	Uses control/fit points
SOLID	Polygon	3/4-vertex filled regions
3DFACE	Polygon	3D triangular/quad faces
INSERT	—	Block references (not yet expanded)

Export (GeoJSON → DXF)

GeoJSON Type	DXF Entity	Notes
Point	POINT
MultiPoint	Multiple POINTs
LineString	POLYLINE
MultiLineString	Multiple POLYLINEs
Polygon	Closed POLYLINEs	Each ring, a hole too, is its own closed outline
MultiPolygon	Multiple closed POLYLINEs	Each ring, a hole too, is its own closed outline

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5. Understanding Coordinate Systems

Most CAD drawings use projected coordinates — eastings and northings on a national, state or local grid — rather than GPS longitude and latitude. Mapplex reads them in the system you confirm and converts them to WGS 84 with that system's shift.

Coordinate Type	Typical Values	What Mapplex Suggests
Longitude/latitude	-180 to 180, -90 to 90	WGS 84, and the geographic systems on other datums for where the numbers fall
National, state or UTM grid	Six- to seven-digit eastings and northings	The grids that place the drawing where it fits, nearest you first
Local site grid	Small values from a site origin	Usually none: enter the definition from your surveyor under Other

Example: A DXF from a civil engineer has eastings near 530,000 and northings near 180,000. Opened near London, CAD Manager suggests the British National Grid as Best. The same numbers opened in Doha match two Qatar grids on different datums; neither is marked Best, and you choose the one the engineer used.

6. Role-Based Access

Role	Import DXF	Export DXF
Owner	✅	✅
Admin	✅	✅
Editor	✅	✅
Collector	❌	✅
Viewer	❌	✅

Note: DXF import creates new project layers, which requires write access. All roles can export.

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7. Tips for Best Results

• Ask your CAD source for the coordinate system — its name or EPSG code is enough; a local site grid needs its definition.
• In a new project, zoom the Map to the project area before importing — the systems there are then suggested first.
• Review the preview table — Not all DXF entities convert to GeoJSON. The import button shows the exact count of convertible features.
• Split large DXF files — Files with 100,000+ entities may take longer. The progress bar and cancel button let you manage large imports.
• Check layer names after import — CAD layers with mixed geometry types are automatically split (e.g., "Survey Points" and "Survey LineString") to maintain valid Mapplex layer types.

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Next: Proceed to Module 13: Engineering Drawing Export to learn how to export schematic drawing pages with your map PDF.