Issue description
Sometimes, in the USA, when you follow the directions to save a .dwg as a .dxf, and explode everything in the drawing, etc. Then when you go to upload to the .dxf to IVION, there’s an error message saying the .dxf is too far away from the site. What can be causing this issue is the units / unit settings in the original .dwg and how that can impact the scale of the drawing after saving as a .dxf and exploding. What is happening is the drawing is scaled by a factor of 12 which is the unit factor between ft and inches.
Scope
This is related to the Vector Map import and .dxf files. Users will need to have access to AutoCAD to evaluate if this issue is possibly occurring.
Pre-requisites
Ability to upload vector maps, knowledge of AutoCAD and units settings, and preferably a license for AutoCAD.
Troubleshooting procedure
Send the .dxf and the original .dwg, if possible. Check the units of the drawing and make sure there isn’t an issue there.
Below is an example of a .dxf with the issue, it could not be imported successfully with all layers into NavVis IVION.
When typing ‘dwgunits’ in the command line, it shows the units are set to Feet.
After typing dwgunits in the command line, the unit for length is <2> which is Feet.
When viewing the drawing settings from the Toolspace, it shows units are set to Feet, more specifically US Survey Feet for any Imperial to Metric conversion. Here you can also see which coordinate system is being used for the drawing if they wish to upload the vector map via spatial reference system and encounter an issue.
When typing Units into the command line, it shows the units are set to Feet.
2 Evaluate the difference in coordinates or any known measurements between the original .dwg and the .dxf they created from the .dwg.
The original .dwg had the proper areas and lengths but notice how the .dxf above appears off. The space ‘9819’ is labeled as 1,810 sqft but if you select the polygon and look at the Properties palette, it shows the area being 260,640 sqft.
Note that 260,640 / (12 inches per foot)^2 = 260,640 / 144 = 1,810 sqft
Therefore, the space is 260,640 square inches in the drawing which equals 1,810 sqft. The issue is that the drawing units are set to feet so dimensionally CAD thinks this space in the .dxf is 260,640 sqft.
Somewhere along the way of saving the .dwg as a .dxf and exploding elements, the dimensions in the drawing were changed to inches while the unit settings remained as feet. This may cause confusion, especially if looking at the drawing settings to see units. At first glance, it could be that IVION is the source of the issue when in fact it is the .dxf conversion / prep workflow prior to importation into IVION.
FAQ
What issue might occur when uploading a .dxf file to IVION?
An error message may appear stating that the .dxf is too far away from the site.
What could be causing the scaling issue in the .dxf file?
The units or unit settings in the original .dwg file may be incorrect, leading to a scaling factor of 12 between feet and inches.
Do I need access to AutoCAD to troubleshoot this issue?
Yes, users will need access to AutoCAD to evaluate if the issue is occurring.
What should I check in AutoCAD to resolve the issue?
Check the units of the drawing by typing 'dwgunits' in the command line to ensure they are set correctly.
How can I verify the area measurements between the original .dwg and the .dxf?
Evaluate the difference in coordinates or known measurements to see if they match between the two files.
Is it possible that the dimensions in the .dxf were changed during conversion?
Yes, dimensions may have changed to inches while the unit settings remained as feet, causing confusion.
What is the significance of the unit settings in the drawing?
The unit settings determine how dimensions are interpreted, which can affect the importation into IVION.
Can the issue be resolved by adjusting the unit settings in AutoCAD?
Yes, adjusting the unit settings to match the intended scale can help resolve the issue.