1- PREPARE CAD FILES
Any CAD files linked into Revit must follow a careful process:
1- Bind XRefs: Xrefs can cause problems. Open the Xref dialog box and bind them all, preventing duplicate layers.
2- Run "Purge": This removes unused layers, linetypes, blocks, etc.
3- Run "Setbylayer": All lines settings should be set to layers, ignoring any color, linetype or lineweight overrides. Use the Setbylayer command to quickly resolve this problem.
4- Freeze Useless Layers: Freeze all layers not required in Revit.
5- Save A Copy: Keep the original DWG file just in case. Save the modified file in a Revit "CAD Links" subfolder.
2- USE LINK CAD, NOT IMPORT CAD
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Now that your DWG file is ready, you can bring it to Revit. You will notice that there is two options to bring the DWG file: Import and Link. Avoid using Import CAD. It makes your model heavier, causing performance issues. Link CAD is better: it loads the latest version of the DWG each time you open Revit and is more efficient to manage the files.
3- USE THESE LINKED CAD FILES SETTINGS
You have many settings to adjust when linking a DWG file. Use the settings below for the best results:
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Activate Current View Only: If left unchecked, the DWG file will appear in all views of the model. In most cases, it is better to import to a single view only.
Colors: Black and White: The default setting is Colors, but you should change that to Black and White. It provides better visibility.
Layers: Visible: By default, all CAD layers will be imported. Set the option to Visible, which means layers that are hidden or frozen in AutoCAD won't be imported.
Positioning: The best way to position DWG file is usually to use Manual - Center option. The Auto - Origin to Origin can also be useful if the CAD file is synched with the Revit model.
4- USE QUERY TOOL TO HIDE CAD LAYERS
Select a DWG file inside your Revit Model. In the contextual tab, you will find the Query tool. Click a line inside the DWG, then use Hide or Delete to make the layer invisible.
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5- SET BACKGROUND OR FOREGROUND
Set the instance properties of the CAD file to Background or Foreground.
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