To successfully and efficiently use AutoCAD objects in a Autodesk VIZ scene, it's important that the files be properly prepared. Specifically, you'll need to pay attention to layer management in the AutoCAD drawing.
In this lesson, you'll clean up a 2D AutoCAD drawing by deleting unnecessary objects and freezing unwanted layers to prevent them from being imported into Autodesk VIZ. You'll also prepare a 3D AutoCAD file for import, taking advantage of the benefits of both Autodesk VIZ and AutoCAD.
The Autodesk VIZ Layer Manager is similar to the Layer Properties Manager in AutoCAD. Both enable you to hide and freeze layers, and to control the visibility and color of objects on those layers. You can also determine whether a layer’s objects are plotted in AutoCAD or rendered in Autodesk VIZ, regardless of the visibility of the objects in viewports.
Once imported, each layer in AutoCAD becomes a new layer in Autodesk VIZ, and each object becomes a new object on its respective layer. Because AutoCAD generally produces a new object with each entity created, this can translate to an enormous number of entities that are imported into Autodesk VIZ. You can significantly reduce this number by converting and consolidating lines into polylines and combining objects into blocks, which Autodesk VIZ then converts into groups during import.
Tip: Objects that you import from AutoCAD with the ByLayer color assigned will maintain that color. Objects with a specific color assigned in AutoCAD will be changed to match the layer color.
Next, you'll learn how to control layers in AutoCAD.
Set up the scene:
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If you are opening the drawing in the latest version of AutoCAD, you will see a warning stating that the drawing was last saved in an earlier version. Click OK.
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You might also see a Proxy Objects Detected dialog while opening the drawing. This means that the drawing was created in another program such as AutoCAD Architecture (formerly Architectural Desktop) and you are missing some Object Enablers. This does not adversely affect this part of the tutorial, so you can click OK.
This is a floor plan drawing of a small condominium complex. You'll focus on the interior views of the lower-right tenant space.
Control the layers:
One thing most people notice about architectural drawings is the fact that there is a lot of information necessary for all the contractors who will eventually construct the building. Hopefully, the architect took advantage of AutoCAD's layer features to separate information and organize the drawing.
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Click the Model tab at the bottom of the window, or, if it's not visible, click the Model button on the lower toolbar.
Autodesk VIZ imports only objects in model space. Objects in paper space are ignored.
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Open the Layer Properties Manager.
If you're prompted to delete filter layers, click Yes to comply.
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Highlight and freeze the following Layers and click OK when done:
The designer who's charged with making the presentation model doesn't need the more detailed layer data pertaining to the electrical or heating, ventilation and air conditioning (HVAC) systems, dimensioning, drawing borders, etc. They primarily need the floor plan of the structure. The layers you've just frozen contain objects that are not required when this drawing is used as a template for building the 3D model.
Tip: Although you can control the layers to be imported in the AutoCAD DWG/DXF Import Options dialog in Autodesk VIZ (explained in another lesson), it is often easier to define the layer states in AutoCAD or AutoCAD Architecture, where you can see the results of the import immediately.
