AutoCADder

The AutoCAD product line manager at Autodesk - Eric Stover - said in the Techworld interview that:

the new DWG format is due in 2009 with the planned release of AutoCAD 2010

So we can expect a DWG format change in a year or so (in AutoCAD 2010). This complies with Autodesk plans to change the DWG file format every 3 releases (= every 3 years).

The interview itself is about the problems some AutoCAD users have with the DWG2007 format (using internal compression) on WAN links with connection accelerators. These accelerators obviously try to save bandwith by caching and skipping unchanged portions of transmitted files. And internal file compression makes the whole file appear as changed.

I wonder how can Autodesk be blamed about this as internal compression is used in many many file formats, not just DWG.

Labels: AutoCAD 2010, DWG, WAN

It seems that in the new 2009-version products Autodesk will get rid of some limitations which were restraining users with the hope of selling higher products.

E.g. the free DWG viewer Autodesk DWG TrueView 2009 now adds the measure tool allowing to measure distances and areas in DWG drawings. This capability was previously limited to the DWF viewer (Design Review) only - so you had to convert your DWG to DWF first. The last Autodesk DWG viewer allowing to measure was Volo View (remember when Autodesk tried to sell the viewer for AutoCAD drawings?).

Another limit falls - AutoCAD LT 2009 will allow to attach raster images (!) and create dynamic text fields - just like the full AutoCAD version. There should also by a 64-bit version of AutoCAD LT.

I am sure that these are results of the pressure of us users - let's get more.

Labels: AutoCAD 2009, DWG, LT 2009, TrueView 2009

If you use AutoCAD 2008, you are probably suffering the same problem - attached xrefs bring in their annotation scale lists and the scale list in the main drawing grows ad infinitum. There can be thousands of nested scales named "XREF_XREF_XREF....".

Such scale lists confuse users (see the SCALELISTEDIT command) and can substantially slow down Open and Xref operations on such infected DWG files. The latest Service Packs for AutoCAD 2008 applications seem to fix the main problem. But what to do with the already affected files? Yes, there is the SCALELISTDEL Reset option or you can use LISP tools like ScaleListDel but still you will have to open the drawings one by one and some of them can open really slooooowly.

The tip Batch remove annotation scale lists may be the cure - the DBXremSL utility does not open the DWG file to fix it - instead, it uses a faster DBX access and modifies all DWG drawing files in a given folder.

The Readme file to DBXremSL mentions a "Safe mode" - I would recommend making this Safe mode the default one so it removes only those scales which were brought-in from Xrefs.

Labels: annotation scale, AutoCAD 2008, batch, DBX, DWG, Xref

My AutoCAD users wanted to have an automatically updated list of Xrefs (xref names) in the main drawing. After some research I have found two methods for doing this:

1. The RTEXT tool from Express Tools - in RTEXT use a predefined Diesel expression for xref list, e.g. $(xrefs,3) or $(xrefs,27,Xref name: )
2. Automatic text fields - in the main drawing insert a textfield (e.g. with FIELD), select the Object properties (category), pick a Xref and select its filename property. You will have an automatic text with the full xref name + path. But you have to to it one by one for all xrefs.
   

Labels: AutoCAD, DWG, Xref

In many drawings, AutoCAD users need to enter texts with special characters like mathematic symbols, letters from greek alphabet, cyrillic, punctuation characters, indices, or just accented characters from other languages.

With the Unicode support in Windows and AutoCAD it is quite easy to enter such characters - either using Windows language support for that particular language (and a local keyboard driver), or by copying the character from the CharMap.exe Windows application (Character Map). Alternatively, you can enter any Unicode character using the \U+nnnn text code.

But for all of this you will need first of all a text font containing a full set of Unicode characters, called "glyphs". AutoCAD ships with a couple of fonts - both SHX and TTF containing the Unicode set. For these special characters you can use e.g. TXT.SHX, SIMPLEX.SHX, or the TrueType font ISOCPEUR. From the Windows standard font set you can use e.g. Arial. If you have MS Office installed, you can use the font "Arial Unicode MS" - it contains one of the largest character subsets of Unicode 2.1 (its TTF file is a whooping 24MB). Try to make sure that the referenced font is available on all target computers used for the respective DWG drawing.

With the Unicode support, AutoCAD offers a very flexible and portable multilanguage text functionality.

Labels: AutoCAD, DWG, font, SHX, text, TrueType, Unicode

The BUDWEISER DWG compatibility benchmark by Xanadu is a well-known test drawing I already wrote about.
Now there is a new "2008" version of this test proving that all the AutoCAD clones based on the ODA DWG libraries and claiming "DWG-compatibility" are still not able to read the AutoCAD DWG format correctly. I have personally very bad experience with DWG files written from Microstation, ArchiCAD and IntelliCAD. In any case be aware that you may potentially lose CAD data - both on reading DWG files into a non-Autodesk software and on writing faulty DWG files from such applications.
You can get BUDWEISER2008.DWG from www.xanadu.cz/budweiser

Labels: AutoCAD 2008, Budweiser, DWG

You may have noticed that - the DWG drawings saved from AutoCAD 2008 are a bit larger than the same drawings saved from AutoCAD 2007 (the format is the same).
One of the reasons is probably the longer list of variables (new system variables in A2008) which are saved in the drawing. Another reason which in my opinion influences the file size much more is the larger thumbnail preview image saved in DWG file.
AutoCAD saves a bitmap (BMP raster) of the current view when saving the DWG file. The pixel size of this raster image (and the resulting byte-size) depends on the aspect ratio of the current view but generally, AutoCAD 2007 and older used sizes below 200 pixels while AutoCAD 2008 saves larger bitmaps of up to 256 pixels. This could add up to 64kB to the DWG file size (comparing to a "no-thumbnail" DWG). Thumbnails can be cut off e.g. in Autodesk DWG TrueConvert/TrueView.

Update: Jimmy Bergmark (JTB World) has sent me information that another reason of the size increase is the reconciled layer baseline table. Can be disabled by LAYEREVAL and LAYERNOTIFY.

Labels: AutoCAD 2008, DWG, thumbnail

DGN-to-DWG and DWG-to-DGN converters were always popular CAD utilities, especially in countries where Microstation was widely used. Exchanging data was always painful process as both applications has used different file formats - DGN (Microstation) and DWG (AutoCAD).

Then Microstation learned AutoCADdish and allowed to read/write DWG files - well writing DWGs was always less than perfect but anyway. At least you could send your DWG files to your Microstation partner and he was able to use it. In Autodesk world, this capability was limited to AutoCAD Map only.

A couple of months ago, Autodesk came with the DGN Translator "technology preview" on labs.autodesk.com (for AutoCAD 2007). And now, reading/writing DGN files is supported directly in the AutoCAD core - and so in all AutoCAD-based applications (also in LT2008). You can import and export DGN files, or even attach them (like xref) with DGNATTACH and clip them with DGNCLIP. Don't forget that only DGN V8 (and XM) format files are supported (unlike in Map) - and there are still lots of older (V7) DGN files circulating around.

So here it is - AutoCAD 2008 - your new DGN/DWG convertor...

Labels: AutoCAD 2008, DGN, DWG, Microstation

Object enablers are one of the most baffling AutoCAD concepts for users. And Autodesk doesn't make it any easier to find and download the right enabler for a given mix of version+objects. The outdated page www.autodesk.com/oe doesn't list any of the applications of the 2007-family (and the 2008-family is almost coming). With more and more AutoCAD versions circulating and more and more users working with the object-oriented 3D AutoCAD flavours it is more important to always find the right enabler if you need to open the object-enriched DWG file in plain AutoCAD or in another AutoCAD flavour.
The Live Enabler function in AutoCAD can lead you through the process of finding and installing the right add-on enabler. But if you need to pre-install a specific object enabler, there should be an easier way to identify and install it.

Labels: AutoCAD, DWG, object enabler