Importing AutoCAD DWG
File menu > Import > AutoCAD (*.DWG)
When you import an AutoCAD drawing file, the software converts a sub-set of AutoCAD objects to corresponding 3ds max objects. After you select a DWG file to import, a dialog asks whether you want to merge objects from the dialog with objects in the 3ds max scene, or replace the scene with objects from the AutoCAD drawing.For AutoSurf or AutoCAD Designer, use the AutoCAD command 3DSOUT to export mechanical models to 3ds max. You can also explode the mechanical models and then import the resulting file, but some data will not appear in the AutoCAD drawing file.

Procedures To import a DWG file:
- Choose File menu > Import. Choose AutoCAD (*.DWG) in the Files of Type list.
- Specify a file name to import.
- Set options in the Import AutoCAD DWG File dialog.
- To import AutoCAD point objects, but not hatch patterns:
- In AutoCAD, freeze any layers containing hatch patterns.
- Import the drawing into 3ds max, making sure that Skip Off And Frozen Layers is turned on and Skip Hatches And Points is turned off.

Derive Objects By group
Layer—Names each 3ds max object based on the AutoCAD object's layer. The layer name is followed by a number for each object from that layer. For example, an AutoCAD object on the layer BASE becomes BASE.01. If Convert To Single Objects is turned on, AutoCAD objects on the same layer become a single 3ds max object.
Color—Names each 3ds max object based on the AutoCAD object's layer color. The AutoCAD color number is followed by a number for each object using that layer color. For example, a red AutoCAD object (Color number 001) becomes COLOR001.01. AutoCAD ignores colors assigned by object in favor of colors assigned by layer. If Convert To Single Objects is turned on, AutoCAD objects assigned the same layer color become a single 3ds max object.
Entity—Names each 3ds max object based on the AutoCAD object type. The object type name is followed by a number for each object converted. For example, an AutoCAD Line object becomes Line.01. AutoCAD drawings can contain thousands of entities, so deriving objects by entity can create many 3ds max objects. If Convert To Single Objects is turned on, AutoCAD objects converted to the same 3ds max object type become a single 3ds max object. Irrelevant info (Modern architecture 3d house building model downloads, 3d home architecture design interior,)

General Options group
Convert To Single Objects—Combines multiple AutoCAD objects into a single 3ds max object. Objects are combined according to the current Derive Objects By setting and their 3ds max object type. Explicit mesh objects are combined. Shapes with no Z axis extrusion are combined, as are shapes with the same Z axis extrusion amount. Shapes with differing amounts of Z axis extrusion are assigned an Extrude modifier and are not combined.
Convert Blocks To Groups—Places all objects in an AutoCAD block into a 3ds max group that uses the name of the AutoCAD block and the number .01. For example, an AutoCAD block named CHAIR becomes a collection of 3ds max objects inside a group named [CHAIR.01].
Multiple insertions of the AutoCAD block are converted to instances of the 3ds max group. For example, a second insertion of the block CHAIR becomes an instance of [CHAIR.01] named [CHAIR.02].
When Convert Blocks To Groups is turned off, AutoCAD block definitions are ignored and block insertions are treated as separate objects, similar to exploding blocks in AutoCAD.
Skip Off And Frozen Layers—Excludes the import of AutoCAD objects on layers that are Off or Frozen.
Skip Hatches And Points—Excludes the import of AutoCAD hatch patterns and point objects.
AutoCAD hatch patterns are made of many short line segments and points. Importing all the objects in hatch patterns can overload your 3ds max scene.
Note: Hatch patterns are stored in AutoCAD drawings as anonymous blocks. Skip Hatches And Points skips any other anonymous blocks in the drawing file. Hatch patterns created in AutoCAD R14 are skipped regardless of this setting.

Group Common Objects—Puts imported objects into a common group, based on how they are derived. In other words, the group would include all objects on a common layer, or color, and so on.

Exporting to AutoCAD DWG
File menu > Export > AutoCAD (*.DWG)
When you export to an AutoCAD R14 or AutoCAD 2000 drawing file, you convert your 3ds max objects into AutoCAD objects. Because AutoCAD doesn't support animation, objects export in a static state defined by the current time set by the time slider.

Procedure To export a DWG file:
- Choose File menu > Export.
- Choose AutoCAD (*.DWG) in the Files Of Type list.
- Specify a file name to export.
- Set options in the Export AutoCAD DWG File dialog (described below).