December 2-5, 2003 ◊ MGM Grand Hotel Las Vegas Autodesk® Revit® File Sharing without Xrefs Lay Christopher Fox BD12-3 AutoCAD® xrefs long ago made file sharing an integral part of CAD management, and fostered a horizontal approach to creating sets of architectural drawings. The single-building-model-per-file organization in Autodesk® Revit® is more vertical, but model linking allows designers to compile campus-size projects efficiently. How do you organize multibuilding projects without x-y-z coordinates? What about phasing? Where do worksets fit in? This basic class will cover the ins and outs of importing, coordinating, linking, and updating information from Autodesk® Revit®, AutoCAD®, and Autodesk® Architectural Desktop® files into your next Revit project. About the Speaker: Chris Fox works as an architectural drafter, illustrator and educator in western New York state. He is president of ArchImage CAD Services Inc., which provides drafting, rendering, design and consulting services to homeowners, design firms and institutions across the United States. He is an adjunct professor at Rochester Institute of Technology, where he teaches AutoCAD® in the Civil Engineering Department and is helping to develop an instructional program using Revit®. Chris is the current president and a longtime officer of the Rochester Area Autodesk Users Group. He has co-authored a number of books on Architectural Desktop® and Revit®. email: [email protected]
Transcript
December 2-5, 2003 ◊ MGM Grand Hotel Las Vegas
Autodesk® Revit® File Sharing without
Xrefs Lay Christopher Fox
BD12-3 AutoCAD® xrefs long ago made file sharing an integral part of CAD management, and fostered a horizontal approach to creating sets of architectural drawings. The single-building-model-per-file organization in Autodesk® Revit® is more vertical, but model linking allows designers to compile campus-size projects efficiently. How do you organize multibuilding projects without x-y-z coordinates? What about phasing? Where do worksets fit in? This basic class will cover the ins and outs of importing, coordinating, linking, and updating information from Autodesk® Revit®, AutoCAD®, and Autodesk® Architectural Desktop® files into your next Revit project.
About the Speaker: Chris Fox works as an architectural drafter, illustrator and educator in western New York state. He is president of ArchImage CAD Services Inc., which provides drafting, rendering, design and consulting services to homeowners, design firms and institutions across the United States. He is an adjunct professor at Rochester Institute of Technology, where he teaches AutoCAD® in the Civil Engineering Department and is helping to develop an instructional program using Revit®. Chris is the current president and a longtime officer of the Rochester Area Autodesk Users Group. He has co-authored a number of books on Architectural Desktop® and Revit®. email: [email protected]
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Revit’s single-building-model-per-file modality does not in any sense mean that designers must work in a vacuum; Revit makes it a simple matter to import--permanently or temporarily--information in other files or formats. For those familiar with AutoCAD or Architectural Desktop, where common usage is to create a separate file for each level of a multi-story building and create floor plans, site plans, elevations, sections and schedules via externally referenced files, Revit offers all the accustomed referencing capabilities. The user can readily perform such standard drafting tasks such as: trace over a sketch or 2D CAD outline, pull floor levels from a 2D elevation, align a Revit model with a CAD model or arrange Revit models on a site.
As of Release 5.1, Revit files can import (static insertion) or link (updatable insertion) vector CAD files of certain types (DWG.DXF, DGN). Revit will import raster image files of certain types (jpg, jpeg, bmp) and link in Revit models. There are different concerns and controls for all four types of reference.
Controls for links and imports are driven from the File and Tools menus. There are no Design Bar or Toolbar items that deal with link management, other than the Cut/Copy/Paste/Delete icons.
• Import/Link dialogues:
File>Import/Link>DWG, DXF, DGN… opens the Import/Link dialogue.
File>Import/Link>Image… opens the Open Image dialogue.
File>Import/Link>RVT… opens the Add Link dialogue.
File>Import/Export Settings>Import Line Weights DWG/DXF… opens a dialogue to edit and save a file translating AutoCAD colors to Revit Line weights for viewing CAD Vectors.
• Link management dialogues:
File>Manage Links… opens a dialogue that lists links to CAD or Revit files, with controls to manage the link status and paths.
File>Raster Images… opens a panel that lists and previews raster files, with a removal button.
Tools>Locations and Coordinates> leads to dialogues to Select or Manage link Locations, Acquire or Publish Coordinates for links, and tools to relocate or rotate project files per links.
We will deal with imports in ascending order of complexity. The simplest type of reference import is a raster file.
• Image Import Dialogue
Menu pick File>Import/Link>Image…
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opens the Open Image file browser:
Only the grips for the imported image appear around the cursor until a left-click selects a location. Then the image appears. Images are imported by view.
Settings
Images in 2D views can be moved, copied, arrayed, mirrored (really a copy across a reference plane), grouped and locked using Toolbar commands. Images can be deleted individually or in groups.
Images have editable properties: name, width and height. The width and height can be independently set if Maintain aspect ratio is unchecked. All copies of an image will reflect a name change, which is a type value; size is an instance value, so each copy of an image in a file is resized individually.
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The Maintain aspect ratio control value for images also appears on the Options Bar as a Lock Proportions checkbox when an image is selected, along with a Flip/Rotate control.
The Horizontal and Vertical flip buttons mirror the image along its midline in the direction specified. The Rotate 90° applies a 90° clockwise rotation to the image. There is currently no way to rotate an image inside a Revit file by any value other than a multiple of 90°.
Visibility
There is no overall visibility control for raster images at the present time, and no load/unload capability. Raster images are controlled by view, on the Annotation Categories tab of the Visibility dialogue.
Location
Images appear in the view in which they are first inserted. Images can be moved geographically within the view without restraint. Images can be copied from view to view with the usual Copy/Paste controls.
Manage Images
The menu pick File>Raster Images… opens the Raster Images list box. This list displays a preview, name and count for each image in the file. There is a Delete button to remove all instances of an image.
If all instances of an image are deleted manually, the image remains in the list box with a count of 0. There is currently
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no way to recall or reload a deleted image using the list box.
• CAD File Link/Import
Revit will translate in vector linework and text (subject to limitations) from Autodesk DWG or DXF format and MicroStation DGN format files. CAD imports appear in Revit as a System Family: Import Symbol. Revit will not import native AutoCAD (ACIS) solids or Architectural Desktop AEC objects. Revit will support 3D surfaces from AutoCAD and proxy graphics from ADT. AutoCAD layout (Paper Space) information is not imported except when Revit does not find supported content in Model Space—then it will show a query about searching Paper Space for usable vector information.
The Site>Toposurface>Use Imported tool explicitly uses imported 3D CAD vector information to create a Toposurface without point-by-point placement.
Dialogue
Menu pick File>Import/Link>DWG, DXF, DGN…
opens the substantial Import/Link dialogue. One file at a time can be selected in the browsing panel and will preview in the Preview panel.
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The Import or Link section of the dialogue provides three controls: a Link (instead of import) checkoff to make the file connection updatable, a Current view only checkoff, which places the import in the current Revit view only (floor plan view but not 3D views, for instance) and enables text importation, and a drop down to control layer import. Choosing Select in the layer control opens the Select Layers dialogue once the Open button is selected in the main import dialogue.
The Scale section provides a drop-down to allow the user to have Revit to find a measurement unit to apply, to select from a list, or to apply a numeric Custom scale factor.
The Layer/Level Colors section of the dialogue controls colors of the imported line work: per the original file colors, reversed, or black on Revit’s default white background.
The Positioning section determines initial placement of imports. The user can Automatically Place a file by one of three settings: Center-to-center, origin-to-origin and by shared coordinates (for links only), or place an import manually. The manual placement option includes a level control that is active when Current view only is unchecked in the Import or Link section of the dialogue.
Revit does not use an “exposed” coordinate system, in that there is no way to specify an absolute position for entities in a file independent of other entities. Revit does track and use the center point of each file, which changes
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as the building model footprint changes. Revit also provide a coordinate location point (unseen by the user) with each project file so that linked files can synchronize positions. Generally the project file that contains site information becomes the basis for shared coordinates.
When placing a linked file by shared coordinates, if coordinates have not been shared previously then Revit uses a default center-to-center placement. The import can be moved readily, and the coordinate location can be shared using its Properties.
Settings
Imported or linked CAD file objects can be deleted, moved, copied, rotated, arrayed, mirrored, grouped and locked using Toolbar commands.
The only property values of a CAD file object that can be altered in the Properties dialogue are the Shared Location and name. We’ll look at Shared Location when dealing with linked Revit files.
When an instance of a CAD link is selected, the Options Bar displays command buttons: Delete Selected Layers/Levels and Explode Imported Instance.
Selecting Delete Selected Layers opens the Select Layers to Delete dialogue. Layers removed this way are taken from all instances of the import.
Selecting Explode Imported Instance converts the import symbol object into individual lines or text. Revit cannot currently explode 3D objects—these will disappear. If the file contains 3D content, Revit displays a warning.
Visibility
The color of layers when importing CAD files upon placement has already been discussed. The menu pick File>Import/Export Settings>Import Line Weights
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DWG/DXF… opens a dialogue to apply Revit line weights to CAD vectors by color. Once settings have been created, they are saved to an external txt file, so that import settings by client or project are easy to apply and edit. The lineweight settings must be applied (loaded) before the CAD import to take effect.
CAD links and imports appear for editing on the DWG/DXF/DGN Categories tab in the View Properties>Visibility dialogue. Each file and its layers can be turned off by unchecking the appropriate check box, and graphic overrides for line weight, color and pattern are available.
Location
Initial placement of CAD files has already been discussed. Imports and links can be moved in the current view without restraint, subject to Shared Location constraints. Files can be copied from view to view.
Manage CAD Imports
There currently is no central control for managing CAD Import objects.
Manage CAD Links
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The menu pick File>Manage Links… opens the Manage Links dialogue, which controls both CAD and Revit files. Here are controls to Unload, Reload and Remove files. One can also Reload From file locations other than the saved ones, and Import a CAD link (similar to binding an AutoCAD xref). There is a button to Save Locations for files which are using Shared Coordinates, and a toggle to switch the saved path to a linked file from relative to absolute. Relative paths are useful where the host and linked files are kept in the same directory and the files, if moved, are moved together. Absolute paths are for network situations where a file will stay in one location for multiple users. The Loaded, Locations not saved and Saved Path fields are read-only information.
• Revit Model Link
Linking of rvt model files is intended to maintain the efficiency of the single-building-per-file module while being able to place building models within a larger site or project development context. Subdividing a multistory building by floors through the use of links is not supported.
Links load into memory, so a file with many links can take longer to open, and system performance can be affected. Individual elements within a linked model cannot be selected, but will perform as references for dimensions and aligning. It is not possible to create constraints between hosts and links. A host file and link cannot be opened in the same Revit session. Links can have links to
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other files—secondary links do not appear in a host model.
Dialogue
The menu pick File>Import/Link>RVT… opens the Add Link dialogue. This dialogue contains options for Positioning and Worksets to open. We’ll discuss worksets in the next section. Automatic positioning options are Center-to-center, origin to origin and By shared coordinates (if coordinates have been previously published or acquired). Manual placement options are to have the cursor at the origin, base point (insertion point for AutoCAD files that have such a point specified) or center of the link. Placing a second instance of a link brings a warning prompt.
Settings
Shared Coordinates and Locations
Linked Revit files can be deleted, moved, copied, rotated, arrayed, mirrored, grouped and locked using Toolbar commands. The only Property value of a linked model that can be altered in the Properties dialogue is the Shared Location value, which is <Not Shared> by default.
Each Revit file contains its own origin point. Linking files means that the host file’s origin is distinct from that of any link instances in it. Sharing Coordinates reconciles origin points. The user can pick the host file’s coordinates (Publish) or a link’s coordinates (Acquire) to establish a shared origin. Generally the coordinates of a site file that is expected to contain more than one building model will be published to the individual linked models.
Picking the Value field for the Shared Location Parameter of a link in its Properties dialogue opens the Share Coordinates dialogue, which gives the user the choice to Publish or Acquire coordinates, and also the chance to rename the default Location that Revit assigns.
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Once coordinates are Shared, clicking on the Value field for the Shared Location Parameter of a link in its Properties dialogue opens the Choose Location dialogue, which allows the user to move the link instance to a named Location, rename the Location, create and name a new Location, or not share the Location of the instance.
The menu pick Tools>Locations and Coordinates>Acquire Coordinates prompts the user to pick a linked model. Revit then acquires the coordinates of that file. If there is no named location in that file Revit supplies a default Location 1. If there is more than one named location Revit opens the Select Location dialogue, as above. The menu pick Tools>Locations and Coordinates>Publish Coordinates prompts the user to pick a linked model. Revit then publishes the coordinates of the host file to the link. If there is more than one named location in the link, Revit opens the Select Location dialogue, as above.
Once Coordinates have been shared, moving a model means that its location needs to be related to a named location, using the Choose Location dialogue, or answering a dialogue about saving the modified location(s) when the host file is next saved.
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Worksets
When a linked file is Workset activated, the user can use the Specify option in the Open Worksets section of the Add Link dialogue to choose which worksets to link. (If the linked file appears in a number of other host files, the user who first opens the file determines the status for all other links.) To change the visibility of worksets, open the Manage Links dialogue, use Reload From… and in the Add Link dialogue choose Specify again to open different worksets in the link.
When a host file is Workset activated, links will be placed in the current workset. If the user creates a Links workset then links in this workset will be loaded only if the workset is opened when the host file is opened. This can save system resources. Note that instances of a link can be placed in different worksets from each other and from the Link Symbol.
Transfer Project Standards
The menu pick File>Transfer Project Standards… opens a dialogue to select Type Categories from one open project to another. If links are present and loaded in a file they will appear in the list of available files, along with any other projects open in the current Revit session.
Visibility
Linked files do not bring in their annotations with them. They will contain Levels, Grids and Reference Planes only.
The View Visibility dialogue contains a Linked RVT Categories tab when links are present. Each linked file and its contained categories can be turned on or off in the current view. All instances will obey these settings. The entire link can be displayed in Halftone. The link or its categories can have the Detail Level be changed from the default By View to Coarse, Medium or Fine. The link or its categories can have the View Range, Phase and Phase filter settings be controlled using settings contained in the link rather then the Automatic settings of the host. For instance, all instances of a link in a Floor Plan view can use a View Range by floor, so they will display the same wall conditions regardless of their elevation in the host file.
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Location
Besides being moved by command, links can be aligned by feature to elements in the host file either in plan or elevation views.
The menu pick Tools>Locations and Coordinates>Relocate this Project will move the host file according to picks (as in the Move command) after displaying an information box. Link instances will appear to move, but as the warning mentions, the project itself and elements not at shared locations will be shifted. This tool, in combination with Shared Levels, allows a model to pick up the base elevation of a site plan.
The menu pick Tools>Locations and Coordinates>Rotate this Project/True North will rotate the host file according to picks (as in the Rotate command) after displaying an information box. Link instances will appear to move. Individual views can then be oriented by Project North or True North.
Manage Model Links
The menu pick File>Manage Links… opens the Manage Links
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dialogue, which has been mentioned before. The RVT tab in this dialogue is the central control to Unload/Reload links, Reload From… to change a link source or change settings such as open worksets, Remove a link from the host, or Save Locations when Coordinates have previously been shared.
