Tuesday, 9 April 2013

Revit 2014 3D dwg in families

Revit 2014 families has the ability to use and explode 3D dwg. Being able to exploded and keep the 3D geometry is new for 2014. This gives new possibilities.

Why is this interesting? It becomes interesting when you are adding Civil 3D into the mix. Civil 3D has the abilities to create 3D solids. This has been difficult for civil 3D for a long time. This has been made easier with the introduction of the sub assembly composer.


For example: let's take a tunnel. part 1,2 and 3 are created from different assemblies. 

Revit has no features for designing alignments like Civil 3D. Therefor we always advise people to model alignment based elements to be modelled in Civil 3D and none alignment based elements to be modelled in Revit Structure.

Next we would like to get this model on to the right coordinates in Revit. Experience tells that Revit can be rather tricky with coordinates. But we are going to use the same techniques we have used before to get Revit models and civil 3D dwgs onto the same coordinates.
We are going to create a dwg with a coordinate marker. You can see the marker already in the image above. The little white thing in the lower right corner. In the image below I have zoomed in a bit.
Of course these coordinates are going to be saved in an external text files, so we can retrieve this in case something goes wrong.

Next we start up in Revit 2014 a generic model template. Import (yes in revit families you are allowed to (must, because there is no other option) import dwg files. In projects this is strictly forbidden)
  • Import the dwg file with manual origin. 
  • Place it anywhere
  • Move the dwg file and put the marker on top of the intersection of the two reference planes
  • goto a front view and check the vertical full alignment


  • Fully explode the dwg
Notice that the dwg is a freeform. This is the only way to get a freeform in Revit. There is no way to create a freeform with native revit commands. Notice the amount of draghandles? 
  • Startup a revit project 
  • go to level 0 or it's equivalent in your template
  • turn on the project base point
  • enter the coordinates you have used in civil 3D. Don't forget to turn them into mm
  • Load the family in the project and place the family in the right position
  • Create generic model schedule (new in 2014) and see the volume
  • Create a section over the model
It's my experience that the section doesn't always work. This has been logged with Autodesk and they are looking into the matter. 




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