File menu > Import > AutoCAD Drawing (*.DWG, *.DXF)
In most cases, when using the same data with two or more different Autodesk products, it's preferable to use the File Link Manager to connect to drawing files; this lets you maintain a “live” link between the applications. However, if you prefer you can also use the Import command to bind to the drawing file immediately.
When you import a drawing file, Autodesk VIZ converts a subset of the AutoCAD, AutoCAD Architecture (formerly Architectural Desktop), or Revit objects to corresponding Autodesk VIZ objects.
After you select a drawing file to import, the AutoCAD DWG/DXF Import Options dialog is displayed. After choosing options and proceeding with the import, you are presented with editable meshes, editable splines, and PRS controllers. Each nested block maintain its parent-child hierarchy and is imported as “Block/Style Parent”. In addition, if a single drawing object creates both mesh and spline geometry, you will find objects referred to as “Linked Geometry” in the scene. Block/Style Parent and Linked Geometry objects appear in the modifier stack on the Modify panel.
Note: If you import multiple drawings, the importer merges the drawings together.
If you are using AutoSurf or AutoCAD Designer, use the AutoCAD command 3DSOUT to export mechanical models to Autodesk VIZ. You can also explode the mechanical models and then import the resulting file, but some data will not appear in the AutoCAD drawing file.
Important: AutoCAD and its vertical applications, such as AutoCAD Architecture (formerly ADT), have custom objects that are unique to the product. In order to view them in Autodesk VIZ, you need the appropriate Object Enabler (OE). Object Enablers let you access, display, and manipulate these objects in AutoCAD, as well as the other vertical applications, including Autodesk VIZ. For a list of downloadable OEs, see the Autodesk Web site
The current DWG import utility contains many improvements, including enhanced DWG compatibility and greater user control and customizability; however, some features were lost from the DWG Importer found in previous versions of the software. For this reason, Autodesk VIZ retains the legacy DWG Import functionality.
The Import Options dialog contains three panels, documented in the following topics:
DWG/DXF Import: Geometry Panel
DWG/DXF Import: Spline Rendering Panel
If you attempt to import geometry that is created very far from the origin or contains a very large bounding box in tools like AutoCAD, the Autodesk VIZ viewports and transform tools do not respond properly. When you use them, the cursor does not move smoothly.
For example, if you have a file that is a mile wide, but your system units are millimeters, you have a scene width of 1.6 million units, which is too great a value. If you change your system unit to feet, this is less taxing on the system.
If any side of the scene's bounding box measures larger than ± 1,000,000 system units, you will see the following dialog:
Autodesk VIZ supports multiple materials per object in DWG files exported as ACIS solids from Revit Architecture/Structure/MEP 2008 and later, as well as solid primitives created in AutoCAD Architecture 2008 (formerly ADT) and later. Imported solids can have Multi/Sub-Object materials that you can view and manipulate in the Material Editor.
Note: Previous versions of Autodesk VIZ supported multiple materials for polymeshes but only one material ID for each ACIS solid when importing a DWG file, regardless of how many material IDs had been assigned to the solid.
Note: Legacy AutoCAD DWG import does not support multiple materials on ACIS solids.
When Autodesk VIZ imports a DWG file from AutoCAD or Revit Architecture (version 2008 and later) with either the Layer, Blocks as Node Hierarchy, Split by Material” or the Entity, Blocks as Node Hierarchy derivation methods, multiple material IDs are readable and editable as Multi/Sub-Object materials in the Material Editor.
Autodesk VIZ reads each face of an imported AutoCAD/Revit solid to determine if it contains any material IDs that can be imported. If the program reads more than one material ID from a solid, it translates each material ID on import and re-assigns it to the object.
The program creates Multi/Sub-Object materials only if it finds more than one material ID; if an ACIS solid contains only one material ID, Autodesk VIZ creates and assigns a standard/architectural material instead.
Note: Autodesk VIZ first evaluates the imported file to find any Revit material IDs, and then looks for AutoCAD material IDs.
Note: If you import a DWG file with the Layer, Blocks as Node Hierarchy, Split by Materials derivation method, it does not split the solid to reflect its materials set.
In earlier versions, Autodesk VIZ read the material ID information from the color ID of the AutoCAD/Revit material ID’s face. Now, it creates a Multi/Sub object material for every translated per face material ID each time you import a DWG file that contains an AutoCAD/Revit solid.
When the program finds multiple materials assigned to an ACIS solid and creates a Multi/Sub-Object material, the Multi/Sub-Object material consists of instances of standard architectural scene materials.
Material IDs are unique within one DWG file. However, the same material ID may appear in two different files, such as Basic Wall: Generic – 12” Masonry. If a naming conflict arises when two scenes are merged, the program applies the last loaded material used in the Multi/Sub object material.
For example, if you import two files, file1.dwg and file2.dwg, and they both contain a material named Brick; the Brick material used is the one from the second file (file2.dwg).
Or, if file1.dwg contains a material named Brick that is internally stored as material ID 222 and file2.dwg contains a different material stored as ID 222, the material used in the scene when they are imported is file2.dwg’s material.
If two solids share the same material ID, they will share the same Multi/Sub-Object material.
DWG ACIS solids import as solid objects in Autodesk VIZ. You cannot separate faces of an ACIS solid object unless you apply the Edit Poly or Edit Mesh modifier.
Tip: You can access the material ID value assigned to this face with the Edit Poly modifier.
ACIS solid materials display in the Material Editor, along with any other imported materials.
When you apply a bitmap material to an ACIS solid, it is applied to every side of the object. For example, a brick bitmap material that you apply to a wall object appears on both sides and all edges of the wall. If you want to apply a material to each face ID, you can use a Multi/Sub Object material so you can assign sub-materials to each face ID.
When you import ACIS solids into Autodesk VIZ, procedural textures are not imported, only materials For example, a brick wall in Revit may have mortar lines procedurally drawn on it in red, but if the object is an ACIS solid, the mortar lines, which are procedural hatches, are lost in Autodesk VIZ
When an ACIS object’s materials are shown as a Multi/Sub-Object material in the Material Editor, each material name appears in the Material/Map Browser, for example, Default wall or Basic Wall: Generic – 12” Masonry.
Polymesh DWGs import as polymesh geometry in Autodesk VIZ. Unlike ACIS solids, you can modify and edit any face of a polymesh object.
When you import a polymesh DWG file, Autodesk VIZ considers each polymesh face as a separate entity, with one material permitted per entity, which allows it to contain multiple materials.
You can apply a bitmap material to the different faces of polymesh geometry, unlike ACIS solids, where you would need to use a Multi/Sub-Object material to create the same effect. For example, you can select the outside face of wall and apply a brick bitmap material and also apply a diffuse material on the inside wall to simulate white paint.
When you import a polymesh DWG file, every material used in the scene appears in the Material Editor as a separate material, where you can edit it.
When the Material Editor shows a polymesh object’s materials, each material name appears in the Material/Map Browser, for example, Default wall or Basic Wall: Generic – 12” Masonry.