2012

Table Of Contents
There is a conversion process required for drawings with lighting prior to
AutoCAD 2007. AutoCAD-based products include a system variable,
3DCONVERSIONMODE, to automatically convert drawings with lighting from
previous versions to the AutoCAD 2007 and AutoCAD 2008 lighting format.
Other lighting fidelity issues include
Lights in blocks. Lights in blocks created in AutoCAD 2008 do not always
display in AutoCAD 2007.
Texture illumination. In AutoCAD 2007 and earlier releases, you cannot
add lighting to textures as in AutoCAD 2008.
Ground Shadows. The intensity of ground shadows in AutoCAD 2008
depends on the brightness of the light and angle of incidence.
AutoCAD Architecture (ACA) Custom Objects
In DWG TrueView, ACA (formerly called ADT) custom objects are not
upgraded
when converting the drawing containing them to a different drawing format.
This is highly desirable.
In contrast, when the ACA Object Enabler is present in AutoCAD-based
products, all ACA objects are upgraded to the latest ACA format. This can
present problems when AutoCAD users on the latest version collaborate with
ACA users that are several releases behind. AutoCAD users can open the ACA
file and save it to the AutoCAD 2004 format used by the previous ACA version,
but now the ACA objects are changed to the AutoCAD 2008 versions. When
these upgraded ACA objects are encountered in ACA, they are treated as proxy
objects.
Additional limitations of Saving to Earlier Versions
Converting a drawing to AutoCAD 2007 format is subject to the following
limitations:
DGN underlays do not display in releases prior to AutoCAD 2008.
Multileaders display as proxy objects in releases prior to AutoCAD 2008.
Converting a drawing to AutoCAD 2004 format is subject to the following
limitations:
Dynamic block geometry can be redefined independent of the blocks
dynamic elements, and the geometry in the block reference is not updated
when the drawing is opened in a product based on AutoCAD 2007 or later.
Understand the Effect of Format Changes | 1845