9

420 Chapter 20: Managing Scenes and Projects
• by freezing their layers in AutoCAD, AutoCAD
Architecture, or Revit before you start 3ds Max
and before each subsequent reloading process.
• by excluding specific layers during the File L ink
Attach/Reload process or Import process so
you do not have to f reeze layers in t he drawing.
This is the preferred workflow.
If you need this type of 2D geometry in your
visualization, try to use polylines instead of
connected lines to get cleaner geometry in 3ds Max
and to reduce the final size of your scene.
3D S olids Objects Linked into a 3ds M ax
Scene
3D Solids objects in a drawing file wil l b e
tessellated (that is, turned into mesh objects with
faces), when you link them into a 3ds Max scene.
The fineness of the tessellation is cont rolled by
the Surface Deviation For 3D Solids setting in the
File Link Settings dialog. A high va lue results in
coarser tessellation. 3ds Max uses less memory
in the scene, but poor approximations of curved
surfaces could result. For acceptable performance,
keepthisvalueashighasyoucan.
Tip: You can change the value of the Surface
Deviation For 3D Solids control at any time by
turning on Show Reload O ptions on the Files
panel of the File Link Manager dialog, and then
adjusting when you reload the file.
Spline Objects Linked i nto a 3ds M ax
Scene
Splines are not rendered in 3ds Max unless they
have rendering parameters applied to them.
Normally, you hav e to collapse a shape to an
editable spline object in order to apply rendering
parameters; however, this is not possible with
spline objects f rom AutoCAD.
Instead, you can apply a Renderable Spline modifier
(page 1–781) to the spline. This lets you set
rendering properties without having to collapse to
an editable spline.
External References and Block Names
AlinkedAutoCADorAutoCADArchitecture
drawing can include xrefs that reference files but
use t he same block names. 3ds Max keeps the
blocks distinct by prepending xref names to block
names.
In Revit, a DWG, DXF or RVT file can be linked
totheproject. ThiskindoflinkiscalledaRVT
Link (page 3–1004).Whentheprojectisexported
to a DWG file, this t ype of link is represented in
the exported d rawing as an external referenced
drawing. In this case, more than one drawing file
may b e created, with one referencing the other(s).
Circular References
An xref file that contains a sequence of nested
references that refers back to the xref file is
considered a circular reference. 3ds Max resolves
xrefs until it detects a circular reference. For
example, if you ha ve the circular reference
A|B|C|A,3dsMaxdetectsandbreaksthe
circularity between C and A. This is consistent
w ith the way AutoCAD or AutoCAD Architecture
handles circular xref dependencies.
Overl ay Ex terna l R ef erences
3ds Max treats overlay xrefs in the same way as
AutoCAD when resolving xrefs.
For more information regarding overlay xrefs,
refertoyourAutoCADUserReference.
Cloning Actively Link ed Objects
If you want to clone actively linked objects,
youshouldonlyusetheCopyoption. Creating
references or instances of actively linked objects is
not recommended, as reliability issues can arise