VisualAnalysis icon
Upgrade to VisualAnalysis 17.0 today. Here's why.

VisualAnalysis 12.0 Help

DXF File Details

Introduction

VisualAnalysis has the ability to import and export .dxf files which is a common CAD drawing format. This drawing format typically contains basic geometry and connectivity information only, not an entire structural model. VisualAnalysis can do only so much with this format! DXF transfers will not support many of the features or properties of your models, but can help you save time in setting up complex models or in getting drawings started after creating a model in VisualAnalysis. 

Disclaimer

Because the DXF format is controlled by Autodesk® Inc., and not IES, Inc., it is not possible to read all DXF files, or to output files to specific format requirements, and these formats may change after our tools have been tested!  The transfer features in VisualAnalysis have been tested with versions of DXF format up to AutoCAD® ASCII R14. CAD systems often use Z as the vertical direction, where VisualAnalysis prefers Y (though it functions with any axis vertical--set it in Project Settings), so you may wish to swap coordinates when importing or exporting.

DXF files are just "dumb" collections of drawing entities--they do not contain a finite element model! VisualAnalysis cannot always guess the intention of these entities and may require your assistance. Before importing your DXF file, check to make sure that the lines connect nicely (don't overlap), that coordinates are reasonable and near the global origin. For best results, split arcs and circles in to lines or polylines where they will cross members or nodes in your final model. You may need to import more than once, experimenting with settings or adjusting the CAD drawing slightly before it imports properly. Even then you may need to work with the project after importing to make a good model out of the data.

Import a DXF File

Use File | Import | DXF File to read a drawing into the current project. You can also use File | Open and select DXF files to start a new project from a DXF file. This is a good way to create a model with complex geometry or to save work when a drawing is available before you begin. There are a number of options when importing from DXF files.

Select items to Import: This allows you to selectively import entities from the file while ignoring others. You can also define basic default properties to items (like member shapes and materials) before importing.

Swap Y and Z coordinates: VisualAnalysis uses Y as the vertical axis by default, while most CAD programs use Z. You can perform this translation automatically. The default is to swap the coordinates.

Units in DXF: Select the units that should be used based on the DXF file.

Scale factor: You can scale the dimensions of the DXF model up or down by a constant factor. Every nodal coordinate position in the DXF file will be multiplied by the scale factor before it is displayed in VisualAnalysis.

The import feature allows CAD entities to be brought into VisualANalysis. This is done through the File | Import | DXF File menu item, or using File | Open and choosing the DXF File type. Upon specifying a .dxf file that was saved from another application, you will see the following dialog:

You have the option of importing DXF POINTS as nodes, LINES, POLYLINES, CIRCLES, and ARCS as members, SOLID or 3DFACE entities as plates. The template to be used for the members and plates may be specified by clicking on the button below the “Set Default” column heading. The name you enter in the template will be the prefix used for all elements and nodes generated of that type.

You may also select which layers in the DXF file to import or ignore.

You can be more specific in your import by just selecting certain layers which will be imported. Other options include changing the units of the coordinates, swapping Y and Z coordinates, and scaling all coordinates by a constant factor. You are also given the option of connecting any crossing lines to create Combined Members (recommended: they may be split later).

Finally, if you have selected CIRCLES, ARCS, or POLYLINES with arcs, you have the option of selecting the number of straight segments each arc or circle will be split into. Circles and Arcs do not 'detect' any crossing lines or points when importing, so it is up to you to specify the correct way these should be split into "chord" lines upon import. For best results you might want to split these into LINES or POLYLINES before creating the DXF file.

Export a DXF File

To save a model, or the visible portion of a model, as a CAD drawing use File | Export to DXF. There are a number of options in the Export to DXF dialog box.

Swap Y and Z coordinates: VisualAnalysis uses Y as the vertical axis by default, while most CAD programs use Z. You can perform this translation automatically. The default is to swap the coordinates.

Units in DXF: Select the units to display information in the DXF file. For the maximum precision, you may want to use a "small" unit like inches or millimeters.

Scale factor: You can scale the dimensions of the model up or down by a constant factor. Every nodal coordinate position in VisualAnalysis will be multiplied by the scale factor before it is written to the DXF file.

Items to Export

Selected items only: Selecting this option (on by default) lets you limit the items exported only to those items that are currently selected.

Using File | Export | DXF File, you may send your nodes, members, plates, and some text labels to a CAD product. Nodes may be exported as CAD POINT objects. Members may be exported as CAD LINE objects. Plates may be exported as CAD SOLID objects. Text will be exported as CAD TEXT objects. The upon selecting File..Export to DXF… menu command you will be asked to specify the location name of the .dxf file to be created.

Note that you have the ability to specify which layers the objects should be placed on. You may also export just the selected objects if they have been selected before the export is selected. Finally you have the option to modify the coordinates that the objects will be specified by in the .dxf file.

Options

Options include swapping Y and Z coordinates, specifying a unit for the exported coordinates, and scaling all the units by a constant factor.