9

Restrictions on Editing AutoCAD Geometry 443
Note:
When Reset Position is applied to a linked
object that has been animated (in other words,
has transform keys for different frames) only the
transform for frame 0 is reset.
See also
File Link (page 3–416)
Inter face
Reset Position—Resets the selected object’s
transforms to those of the original AutoCAD
object when the drawing was last reloaded.
Restrictions on Editing AutoCAD
Geometry
Many operations that are allowed on mesh, spline,
or shape objects in 3ds Max are not allowed on
linked AutoCAD geometr y, and other operations
behave differently.
The following operations are not allowed on linked
geometry:
•Deletion
• Altering the p arent-child hierarchy
• Collapsing the linked geometry into an editable
mesh or an editable spline
If you must perform any of t hese operations, you
must either do them in AutoCAD or else bind the
drawing data to 3ds Max, which breaks the link
back to AutoCAD.
Apply ing Modifiers to Link ed AutoCAD
Geometry
You can apply modifiers to linked AutoCAD
geometry and these modifiers will persist when
you reload the geometry. This can be a very
powerful way to intelligently manage your design
intent, but it can also lead to some unexpected
results, especially when using topology-dependent
modifiers.
“Topology-dependent” s imply means that the
modifier is relying on the particular arrangement
and number of faces and vertices that comprise the
mesh representation of the object. It is common,
for example, for the modifier to cause an action to
be performed on the nth elementitencounters,
say the “twelft h” face or the “fourt h through the
twentieth” vertex. It is easy to perform ed its on
the base object in A utoCAD that would cause the
definition of the nth element to change, which
would result in the modifier yielding unexpected
results when the dr awing is reloaded in 3ds Max.
Not all modifiers are topology-dependent. When
you attempt to use a topolog y-dependent modifier
on lin ked AutoCAD geometry, a warning dialog
is displayed that gives you an opportunity to
continue or abort the operation.
When you use modifiers on linked AutoCAD
objects and blocks, remember that the VIZBlock
object you see in 3ds Max does not contain
anygeometrydirectly;applyingmodifiersto
VIZBlocks will never have any visible effect.
Instead, apply modifiers to the component
objectsbelowtheVIZBlockinthe3dsMaxobject
hierarchy.
Copying Actively Link ed Objects
Yo u c a n copy actively lin ked objects in 3ds Max;
the copies are automatically converted to editable
mesh objects. If your selection contains several
objects that instance another object, the resulting
copies also instance the same object.
However, it is recommended that you do not
instance or reference actively linked objects, as this
can introduce instability to the scene.