Designing DXF Files for Optimal Processing
To ensure a smooth and efficient workflow, it's crucial that customers provide correctly formatted DXF files. This guide outlines the required design specifications for each component type to minimize errors and reduce custom work by our in-house team.
General Requirements
No 3D Components:
Ensure all elements are in 2D. Before saving, use the FLATTEN command to eliminate any unintended 3D elements. If you do not have the full version of CAD, this can be done in QGIS using the Set Z value command and setting it to 0.
3D solid block elements are not supported.
Single Entities per Component: Each component must be represented as a single entity (polygon, closed polyline, line or point).
No Overlapping Elements: Polylines, lines and polygons should not cross or overlap incorrectly in the same layer.
Layer Organization:
Each component should be assigned to a separate layer.
Multiple layers can be selected for a component, but you can't place multiple components in a single layer.
The CAD drawing should be georeferenced as the EPSG needs to be provided on upload to the platform.
Blocks are supported. Blocks, including nested blocks, are expanded automatically on import, so you no longer need to run the EXPLODE command before uploading. Note that only drawing geometry inside a block is imported — any text inside a block is discarded.
Xrefs are not supported. Any Xrefs should be inserted in to the main CAD file and all Xref links deleted.
The drawing should be purged before saving to remove un-required layers.
The CAD file needs to be provided as a DXF 2010 version.
The DXF should be <500MB, if you have a large number of components in your drawing, you may need to split the drawing into several files for upload.
The file should have less than 200 layers.
What Sitemark Reads From Your Drawing
Lines and polylines are imported as drawn. A polyline that closes on itself is imported as an area.
Curves — arcs, ellipses, and rounded (bulged) polyline segments — are imported as smooth curves. You do not need to straighten or explode them.
Points are imported as drawn.
Splines are not imported. A spline is skipped entirely, so its component will be missing from the platform. Convert splines to polylines before exporting — every CAD tool has a command for this (in AutoCAD, SPLINEDIT and then Convert to Polyline).
Circles are imported as a single point at the centre of the circle, not as the circle itself. If the shape of the circle matters, draw it as a closed polyline instead.
Text is not supported. Any text in the DXF, including text inside blocks, will not be displayed on the platform.
Hatches are not supported. The platform cannot display hatches, so there can be no hatches in the CAD file.
Component-Specific Design Rules
Panels
Must be drawn as separate polygons or closed polylines.
A number of panels cannot be represented by a roster of crossing lines.
If you use closed polylines, they will be converted by Sitemark into polygons automatically.
Piles
Must be represented as points.
Roads and Trenches
Preferably drawn as areas: a polygon or closed polyline that follows the true outline and width of the road or trench. Drawing them this way lets Sitemark compare what has actually been built against your design, and report where the built work deviates from it in width or position.
Centre lines are still accepted: a road or trench drawn as a single line or polyline along its centre is imported and tracks construction progress as before. Sitemark cannot measure its width or position, so no deviations are reported for it.
Use one style per layer. Do not mix area outlines and centre lines for roads or trenches within the same layer, as this produces unreliable deviation results.
Do not draw a centre line as a closed loop. A centre line that returns to its own starting point — an earthing ring, for example — is read as an area rather than as a line. Keep these on a separate layer from the roads and trenches you want to track.
Already have a centre-line design in Sitemark and want deviations on it? Contact our Sitemark team, we’ll plan the switch with you.
Fences
Must be drawn as lines or polylines.
Foundation Beams
Must be drawn as separate polygons.
Tables
Must be drawn as separate polygons or closed polylines.
If tables are represented as closed linestrings, ensure the last point connects to the first point to form a closed shape. These will be converted into polygons automatically.
Other Components
Can be represented as polygons, polylines, lines, or points, but each must be a single entity per component.
By following these guidelines, you can provide DXF files that integrate seamlessly with our system. If you have any questions, feel free to reach out to our support team.