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Organizing the AutoCAD File

You'll need to identify the information in AutoCAD that you need for SketchUp and discard the rest. The useful AutoCAD linework will be reorganized on appropriate layers. Other linework will be isolated and discarded. This includes organizing and including linework from AutoCAD XREF files.

The AutoCAD layers and the information on those layers will directly transfer into SketchUp when they are imported. All of the AutoCAD information will be organized on specific layers to establish layer organization in SketchUp. Therefore, the basic organization of layers as outlined in SketchUp Process Modeling is accomplished in AutoCAD prior to importing a model into SketchUp.

The organized CAD linework will be broken into two categories:

• Linework that defines the surfaces of the site plan and creates the Flatwork Base.


• AutoCAD blocks that define individual objects, site elements, and vegetation.

The two categories of information will be broken up into two separate AutoCAD files. These files are then imported into SketchUp.

• One file contains the linework that defines the Flatwork Base.


• The second file contains the AutoCAD Blocks.

Generating the Geometry

The AutoCAD linework that composes the Flatwork Base is imported into SketchUp first. The imported linework is then used to generate faces and surfaces.

There are two different methods you can use to heal the bases to create faces:

• Use the Line tool to heal faces.


• Use five custom Ruby Scripts, known as AutoCAD Cleanup scripts, to create geometry from the AutoCAD linework.

After you create the base geometry, you can add color and Push/ Pull surfaces to create the volumes and add detail.

Arranging the Objects

The last step is to import the second AutoCAD file that contains the blocks of site elements, furnishings, and vegetation.

As with layers, AutoCAD blocks import directly into SketchUp. Once they are imported, AutoCAD blocks instantly become SketchUp components. This means that all versions of the block are now components; they can be edited to affect all the other similar blocks/ components in the model.

The last step of the conversion process simply replaces the 2D linework of the imported CAD blocks with 3D SketchUp components. This allows you to instantaneously and accurately arrange many types of site objects in a model.

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This article is excerpted from Google SketchUp for Site Design by Daniel Tal, copyright © 2009, with permission of the publisher, John Wiley & Sons.

Daniel Tal, ASLA, is a practicing landscape architect in Denver, Colorado, and a SketchUp specialist who conducts workshops and seminars on SketchUp for landscape architects and architects. Daniel also consults on SketchUp tools and future SketchUp developments to meet the needs of landscape architects and architects, and helps beta-test SketchUp releases.

SUBSCRIPTION SAMPLE When AutoCAD layers are imported into SketchUp, they retain their layer names and information. Image: Daniel Tal/ Courtesy Wiley Extra Large Image To simplify the model-building process, the contents of the AutoCAD drawing can be saved as multiple individual files that are incorporated sequentially into the SketchUp model. Image: Daniel Tal/ Courtesy Wiley Extra Large Image First, the drawing elements representing the site's surfaces and contours are imported and converted to SketchUp faces. Image: Daniel Tal/ Courtesy Wiley Extra Large Image Next, the 2D faces are extruded, shaped, and assigned colors. Image: Daniel Tal/ Courtesy Wiley Extra Large Image Then the file containing the AutoCAD "block" objects — representing trees, benches, and other landscape elements — is imported, and an equivalent 3D object from the model library is selected to replace each type of "block." Image: Daniel Tal/ Courtesy Wiley Extra Large Image Each type of 2D "block" entity can be edited. Pasting in a 3D library object into the block is a quick way to add detailed elements to a model. Image: Daniel Tal/ Courtesy Wiley Extra Large Image The edits made to a given "block" type apply across all instances of that block type in the model, in this case quickly populating the model with trees. Image: Daniel Tal/ Courtesy Wiley Extra Large Image Google SketchUp for Site Design by Daniel Tal. Image: John Wiley & Sons Extra Large Image   Click on thumbnail images to view full-size pictures.