Dynamo to create simplified linework of AutoCAD furniture meshes?


Is Dynamo capable of automating the processing of furniture families that have overly complex DWG geometry?
For example, manufacturers often send us 3D models of chairs that contain far more detail than we want to see in a plan view, but want in our models for rendering purposes. I’d like to automate the process of generating a hidden-line plan view of a complicated DWG chair, extract that 2D linework, and place in the “top” view of the chair as symbolic linework, and of course set the visibility of the DWG object to be hidden in plan and RCP but visible in 3D.

Is this possible? I think there’s a way to do this in AutoCAD, but I left that disaster-zone of a software 15 years ago and dont want to go back if possible.


You might be able to have it pull the outlines of the mesh as solid but there would be no internal details. Often the same manufacturer have 2D linework of their furniture. You could use that instead. Might be a lot easier!


(I have zero experience with Dynamo, other than running scripts others have created)
Usually for a chair, all we want is the outline. what node exports a current view to create the linework or solid?
The only thing I’ve found that sounds close is the export to SAT.


Can Dynamo activate external add-ins? If so, it seems like the “Freeze Drawings” add-in functionality could be used to “flatten” the plan view to get an accurate 2D representation of the model that could then be exploded as symbolic lines.


You’ve chosen a not so easy task for your first graph!

If you want the mesh flattened you could probably find the edges of the mesh and then project them onto a plane. It’ll be messy though since you’ll be getting all the edges but it would give you something you could then pull the outer most lines from, manually, if not through Dynamo.


Can you upload a sample file of what you are wanting to run this on?


Since I’m a new user, the forum wont let me upload yet…


Google Drive, wetransfer, dropbox, box, bluebeam session

there are several ways to share a file :slight_smile:


of course… just trying to keep the file here.



Here is a simple way in Revit and AutoCAD (I know you said you did not want to use AutoCAD, but it works!):

  1. Draw rectangular extrusion in the “Ref - Plan” view of the family. Make this box larger than the chair in plan.
  2. Change its bottom offset to be -1’ and the top at 0.
  3. Assign a material to this extrusion with a solid surface pattern set to some color. I use blue.
  4. Export this view to AutoCAD.
  5. In AutoCAD, the hatch will be trimmed around the mesh projection of the object. Simply delete the other linework and keep the hatch.
  6. Click on the hatch, right click and select the “generate boundary” option. This will trace the hatch as a polyline.
  7. Delete the hatch. Explode the polyline, and delete the exterior box of the shape. This leaves you with the interior trace around the object.
  8. Import into the plan view of the family using the “Current View Only” setting. Explode if desired. (Warning: some small lines may when deleted when you explode)


Well, if it’s Haworth we’re talking about… their RFA files are native Revit (most of them anyway) so it should look good in all views by default. I can’t open the linked RFA (2016 only on this computer) but the name makes me think its this product – http://www.haworth.com/resources/symbol-search/105. Check out the file linked under the RVT text (they’re all the same file I think).

Doesn’t answer your larger question though.


Thanks, but the whole point is to automate the process to handle folders full of families that have this problem. We’re trying to cut AutoCAD out of the process, unless it can be part of an automatic workflow.

The Haworth example was just posted as a sample family with a mesh in it, but we have a lot of DWG and DXF stuff in our library that isn’t readily available from a manufacturer.

Any luck with the file I posted?

Thanks all for the comments.


Yeah, that mesh is a mess. :laughing: I took a look at simplifying it to a BREP, but failed. I will try to see what I can do when I have some more time.

The essence of this workflow is shown in a tweet from @Zach_Kron .


I dont “read Dynamo” well enough yet to know what Zach’s process involves…

My thought process goes something similar to Rafaels for Autocad, but dont know if Dynamo can do it with Revit…

in a 3D view, rotate to the top view orientation
Set Silhouette linetype to something specific that can be extracted, and thereby separated from the internal mesh lines.
Set view style to hidden line with Silhouette setting on.
(these steps are similar to the “freeze view” add-in)
Export view to DWG
Reinsert DWG to Plan Reference view
explode DWG
Select and delete all linetypes other than the Silhouette linetype
Set visibility of model objects to be hidden in plan views

Piece of cake, right?


So you want just a 2D representation?


And by the way, aren’t most DWG meshes a mess? :slight_smile:


For plan views, yes, just a 2D representation, but the mesh objects visible in 3d views.