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DXF-Import

Data for object geometry provided in the DXF-format (DXF: "Data Exchange Format") can be used to set up a model in CadnaA. Due to the ongoing modification of the DXF-format by Autodesk, the manufacturer of AutoCAD, a DXF-file may contain various objects (e.g. lines, polylines, 3D-objects etc.). Basically, a DXF file is a text file with ASCII-compatible type range which can also be displayed in an ordinary text editor.

Prerequisites

To ensure a smooth import to CadnaA the following rules should be observed by the DXF-file:

  • Different object types are on separate layers.
  • All objects superfluous for the object representation (e.g. text frames, fiducial marks, auxiliary lines etc.) are deleted from the drawing.
  • Polygon objects (e.g. buildings) are stored as polylines.

Note

Polygon objects not been saved as polylines consist of a multitude of individual lines which can afterwards - if necessary - be closed with the command „Close Buildings“.

  • Open polygons (e.g. roads) have been saved as such.
  • For roads, just the central axis is relevant since the road width is entered in CadnaA as road parameter.

Example

Example

Path: Import/DXF/buildings_roads.zip

In the following example buildings and roads are imported from a DXF file. Proceed as follows:

  • Unzip the file
  • Select on the dialog File|Import the file type „DXF (AutoCad)".
  • Click once (!) on the file name and then click on button „Options“ on dialog Import File.

The dialog Options for DXF-Import is displayed. On the table, each CadnaA object type can be assigned to a single layer in the DXF file. In this example, roads and buildings are to be assigned.

  • Double-click into the table row "Road".
  • Select from the list box „Layer“ in the dialog Import:Layer the layer name „ROAD“. Subsequently, all objects on this layer are assigned to the object type „Road“.

Selecting the layer ROAD for all roads

  • Double-click into the table row „Building“.
  • Select from the list box „Layer“ in the dialog Import:Layer the layer name „BUILD“". Subsequently, all objects on this layer are assigned to the object type „Building“.

Selecting the layer BUILD for all buildings

  • Activate the option „Use Object Height for Polylines“ on the bottom of the dialog.

Option „Use Object Height for Polylines“ activated

  • Close the dialog Options for DXF-Import with OK.
  • Launch the import procedure by click on the button „Open“ on dialog Import files.

  • If you do not see any objects in CadnaA engage the display of the entire limits (symbol: ) or click via menu Options|Limits the button „Calc“.

  • Press the key combination CTRL+3 to display the objects visible on the screen in 3D-Special view.

Via the building’s table (menu Tables|Obstacles|Building) you may check whether the building heights have been imported (column „Height“). The road widths, however, have not been imported since the geometry data refers to the roads axis only. The road width can be imported via ODBC, e.g. from spreadsheet tables.

Imported roads and buildings