Exporting Revit to CAD - Layer Mapping advice??

[evelyn]

I started in a new office working along side a CAD manager. We have engineers that use Revit and autocad. I prefer to work in Revit, mostly because it helps me understand the building components better and its easier for me to use, however some of our drawings have to be done in autocad.. Also there is a graphic difference in drawings. Our revit drawings do not look like our office standard drawings that have been created in autocad. I have been researching layer mapping, which to my understanding is an option to assign specific layers to objects when exporting. I am having a difficult time understanding how to use this, it seems very powerful. Is there anyone out there that has used layer mapping custom to office layers/linetypes? How did you set this up in revit?
Thank you so much for your help!

[marmiketin]

The best thing to do is to set up all your layer mapping in your Revit Template file so that it will be setup every time you start a new project. You setup your mapping like this
Layer Mapping.png
Once you have set this up to the way you want you can save it as a mapping type. You can have several different mapping setups for different purposes.
One issue with this is that if you have families that are built from imported CAD objects, everything CAD in that family will be assigned to a layer G-IMPT and you cannot map this layer.
For any and all layers that do not get mapped you need to then use the layer translator in AutoCAD to change the layers you want. Layer Translator setups can also be saved and imported so you do not need to remake the layers ever time.

[evelyn]

Thank you so much for your help. This is the write track I want to be on.. Once I have created the 'export set up', then saved with our office standard layers, future export drawings will be more uniform. My goal here is that once a drawing is plotted, its almost impossible to guess which software it was drawn in. All of our drawings will look the same, as far as line weights etc. Also if opening the exported dwg, the layers match to office standards.

Will I need to set up each layer in revit? Or is there a way to load the layer properties from Autocad? I see the option to load from file, but I am not sure how this would work.

THank you again! Happy Friday

[marmiketin]

Unfortunately you cannot load layer properties from AutoCAD into Revit. Their are a few standards that come with the Revit install (AIA Standard is one of them) and you can likely find more online but you cannot export what you create or modify to its own standards file. It is a time consuming proccess to map all the layers but once it is done once and you should not have to do it again. You can also transfer standards using the transfer project standards tool in Revit from one project to another or to your project template file.

[tedg]

Another option is to use AutoCAD's Layer Translator (command: laytrans).

Assuming you have an AutoCAD template (.dwt) set up the way you want it with layer names, line wights, etc..
Once you've mapped all your layers with the proper names etc in Revit,

After you have exported your file(s) to AutoCAD from Revit, you simply run the translator in each file and map your layers properly.
Once you've done this once utilizing all the possible layers, you can save an AutoCAD standards file (.dws) and use it (load it in layer translator) over and over without having to map the layers individually.

Another option is simply insert your Revit exported dwg into a blank dwg which contains all your layers, they should take on the proper layer properties if they have the same name and all are set to ByLayer.

HTH

[marmiketin]

The one thing to be weary of when using a saved layer translator file is that if you did not include every possible translation (say you missed translating site elements) you cannot add it to your already created translation file. The translation file can only be overwritten with translations you are doing at the time and will forget any that were previously saved but not in use at the moment.

[evelyn]

Thank you so much!