Truview 2024 conversion

[autoid374ceb4990]

A client using R14 sent me a DWG file, a topographic map with just contour lines.  The file was 34MEG.  The header in the file said it was version AC032, whatever that may be (2018-2024??). I loaded it into Truview and got the message "This DWG file was saved by an application that was not developed by Autodesk.  What do you want to do?" I continued and converted the file to R14.  Now the file is 120 MEG.  I loaded it into R14 and found that each contour line was an individual BLOCK.  I exploded all  the contour line BLOCKs, did a purge, and saved the file.  Now it is still 119 MEG.  I then did a WBLOCK exporting just the contour lines and created a new DWG file, but that did not reduce the file size.  The only entities in the file are POLYLINEs.  Is there some reason that the R14 file is so much larger than the AC032 file?

[dmfrazier]

(I assume you have turned on and thawed all layers.)

Count the objects (entities) in your drawing. That might explain the file size.

If it doesn't, perhaps there are invisible objects in the DWG.

[pendean]

If you both use R0014, why did you have to process the file through DWGTRUEVIEW?
Did you ask the file creator aka client why the header read AC032? Seems like you two ought to engage together.

As a general rule, DWG files from newer versions saving back down to older versions create larger files: especially if the original file has content from AEC variants of AutoCAD (and other database designed to be round-tripped back to the newer version).

Why don't you just use WBLOCK command to create a new file only from the items you wish to keep in modelspace? manually select those objects with a window instead of trying a "select all" option.

[autoid374ceb4990]

Only 3 layers, all turned on and thawed. 1270 polylines (contour lines) in the drawing

My client is using R14 because of the software add on he uses, but he received this AC032 file and needed it converted to R14, so I converted with Truview.  I tried WBLOCK by selecting with a window and that did not reduce the file size.

I did find 595 ATTRIBUTE definitions, erased them, still did not reduce the file size.  Tried a DXFOUT and read it back in, still around 120 MEG file.  Original AC032 file was 33 MEG.  Is the file format on the newer versions compressed?

[autoid374ceb4990]

I went back into Trueview and converted the AC1032 file (34 MEGS) to a 2004 (AC1018) file and it was 39 MEGS.  I then converted it to a 2000 (AC1015) file and it was 121 MEGS.  So it appears to me that sometime between 2000 and 2004 the file format was changed.  The file converted to R14 WAS 121 MEGS. The polylines in this file have very,very close vertex spacing, so I guess I will have to look for a LISP routine that works in R14 to reduce the number of vertices.

[pendean]

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@autoid374ceb4990 wrote:

...but he received this AC032 file and needed it converted to R14...

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It's best if you both need to reach our to the file originator/creator and ask them for a clean conversion from their software: if is it AutoCAD based, AECTOACAD command is the command they need to use, and select R0014 format.

But as I noted before, typically the farther back a DWG file is saved the larger the DWG file is going to be, and there is nothing much you can do about it for the most part other than removing content (perhaps your 121MB file needs to be 3-4-5-10 xref instead for example).

Best of luck with it all.

[autoid374ceb4990]

OK, what is "3-4-5-10 xref".

[autoid374ceb4990]

Not that this really matters, but I could not find a LISP program that worked with R14, so I wrote one (ARX) that removed every other polyline vertex, and that reduced the file size from 121 Meg to 39 Meg. Still does not make sense to me that reducing the polyline size by 1/2 would reduce the file size so much, but my client can live with 39 Meg.

[m_latz]

If I remember correctly, there was a new element spline from the AutoCAD version 2000, before there was only polyline.

What I could imagine is that the tolerance with which a spline is converted to a polyline has been changed/reduced. Or the algorithm was optimized after version 2000.

To analyze this, you would have to copy a few elements from the original drawing and then test them with it.

regards

Markus

[autoid374ceb4990]

Actually there was a SPLINE available at least as far back as R14.

[m_latz]

Yes, you're right. I looked again in the old documentation, from version R 13 I find the spline element.

regards

Markus