AutoCADder

AutoCAD is able to export KML/KMZ models to Google Earth already for some time (since version 2007 and its GE Extension). The recently released new version of the Google Earth Extension for AutoCAD 2008 adds very interesting functions to the previous plain PublishKML command.

One of the new functions allows to work with the "4th dimension" - you can add timespan attributes to your published models and then use the time-slider in Google Earth to animate the building process, the existing/new changes, etc.

Another new function is IMPORTGEMESH. This command imports a 3D model from Google Earth window to a 3D mesh in AutoCAD. The model has even attached materials (the raster images - aerials) so you can simply render it.

This is a very nice add-on for AutoCAD - a must for any civil engineer.

Further reading:
http://autodesk.blogs.com/between_the_lines/2007/05/publish_to_goog.html (announcement)
http://labs.autodesk.com/utilities/google_earth_extension_beta/ (download)
http://www.cadforum.cz/cadforum_en/qaID.asp?tip=5593 (step by step)
http://earth.google.com (Google Earth)

Studying the DXF Reference can reveal some interesting features built in AutoCAD which are not available in the common user interface (in the standard menu/dialog UI).

Did you e.g. know that you can set raster images to display only in aligned plan views? If you have a raster image representing a underlay scale, reference, logo, etc. - maybe it makes no sense to have it displayed in 3D views, perspectives and rotated views. The AutoCAD drawing database (DWG) has a setting for hiding such images in views not aligned with screen (non-plan views).

You can use the following simple LISP macro with the IMGNA (image not aligned) toggle command to demonstrate this functionality. Please note that there is no internal user command or setting to control this feature in AutoCAD.

; Hide image when not aligned with screen
; AutoCADDer - http://autocadder.blogspot.com
; Original LISP rewritten by R.K. McSwain
;
(defun C:IMGNA (/ e val msg nv)
(setq e (entget (car (entsel "Select an image: "))))
(if (eq 2 (logand 2 (setq val (cdr (assoc 70 e)))))
(setq nv (- val 2) msg "\nThis image will be hidden in non-aligned views")
(setq nv (+ val 2) msg "\nThis image will be displayed even in non-aligned views")
)
(setq new (subst (cons 70 nv) (assoc 70 e) e))
(entmod new)
(princ msg)
(princ)
)

Labels: AutoCAD, image, LISP

Many users transferring customizations from older AutoCAD LT versions have problems with the changed file names in AutoCAD LT 2007 and LT 2008. Please note that your hatch patterns, linetypes, command aliases are no longer in the ACLT.PAT, ACLT.LIN, ACLT.PGP files (or the ISO-equivalents) but rather in the ACADLT.PAT, ACADLT.LIN, ACADLT.PGP files (or the ISO-equivalents). So the base name for the AutoCAD LT files has changed from "ACLT" to "ACADLT".
A small step for file system, a giant leap for customizers...

Many people believe that Windows Vista makes more RAM available for your CAD programs. But if you compare the most common versions of Windows XP and Windows Vista, nothing has changed in terms of memory limits. The 32-bit version of Windows XP and Vista 32-bit share the same application memory limit of 2GB (or 3GB in special modes).

If you need more memory - what you always need when working with large CAD data - you have to pick the 64-bit version of Windows. But again, the 64-bit version of Windows XP and Vista 64-bit share similar memory options. Even in the 64-bit OS a 32-bit application cannot use more than 4GB of RAM; native 64-bit applications can use virtually unlimited memory. So remember - Vista doesn't bring higher memory limits, the 64-bit operating system does.

There is one more difference between WinXP and Vista - the way you control the 3GB memory mode. If your 32-bit application supports this mode (e.g. AutoCAD, Inventor, Revit, Civil3D...), this mode makes 3GB of RAM available for it. In Windows XP, this mode is switched on through the BOOT.INI config file (/3GB). In Windows Vista, you can switch this mode with the BCDEDIT config tool - as described here (bcdedit, not bsdedit) or here.

Labels: 32-bit, 3GB, 64-bit, AutoCAD, RAM, Vista

As I predicted a couple of months ago, Autodesk has indeed released a LT version of Inventor. What I have not presumed is the price - expected low price fell below any limit - Inventor LT is free (at least for now - about 999$ when released).

Inventor LT is based on the same kernel as full Inventor. As with AutoCAD LT, this LT version lacks some of the more advanced functions of the full-blown version and most of the customization options (add-ons). Inventor LT doesn't offer assembly modelling, sheetmetal design, doesn't come with the Content Center and of course doesn't include AutoCAD Mechanical and Vault.

Other than this, it seems to support all 3D modelling and drawing creation functions of the full Inventor 2008 and its file formats. You can work with DWFs, you can even use the newly released Translator plugins for Parasolids, UG-NX, Pro/E and Granite file formats.

Inventor LT can be downloaded from the redesigned labs.autodesk.com site.

Labels: Inventor, Inventor LT