Question

Is there a way to extract extents from AutoCAD drawings? These are held in drawing system variables $EXTMIN and $EXTMAX.


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6 replies

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For as far as I know, there are no parameters that can be read from the reader that contain the extents. You could use a BoundingBoxAccumulator to extrect the full extents of the drawings or a selection of the objects in the drawing.

Userlevel 4
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I think Lars is correct. The only parameter I see that might help is called "Read Drawing System Variables" - but I don't know what information is read, or whether such variables include the extents.

I also checked in our databases and I don't see any suggestion that we expose this information to the user or have had any requests. If you would like to see this implemented, please post an idea to the knowledge centre and we'll consider whether it can be done.

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I saw the "Read Drawing System Variables" option but couldn't see a way to "write" anything that was read from there -- so I'm not sure what the option does now. It would be useful, at least to me, to be able to write out variables such as the $EXTMIN and $EXTMAX.

Ed

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I saw the "Read Drawing System Variables" option but couldn't see a way to "write" anything that was read from there -- so I'm not sure what the option does now. It would be useful, at least to me, to be able to write out variables such as the $EXTMIN and $EXTMAX.

Ed

Hi Ed,

 

 

I am getting a little confused by your last post. In your question you state that you want to extract them, so I think you want to read them. In your last post you say that you want to write the parameters.

 

Also I am curious towards the values that are written into the parameters, especially since you say you want to write them. If they contain the extents of the drawing, than I would not expect it to be possible to write them, since they probably will be calculated by AutoCAD itself when the drawing is saved.

 

However if you are able to set them your self, then I would expect them to be the values of what will be shown when you open the drawing.

 

 

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My bad about the "write to". What I'm hoping to do is read the $EXTMIN and $EXTMAX values from an AutoCAD drawing header and then write these values to an output location --- like a table.

Userlevel 2
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For FME 2018, we have added the $EXTMIN and $EXTMAX values to the drawing system feature produced when the Advanced Parameter "Read Drawing System Variables" is enabled on the AutoCAD reader. The values will be available in the following attributes on the drawing system feature:

  • autocad_extmin_x
  • autocad_extmin_y
  • autocad_extmin_z
  • autocad_extmax_x
  • autocad_extmax_y
  • autocad_extmax_z

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