Create dwg w grouped plines from closed mesh?

Rhino Rhino for Windows
1

Hi,
My first post so be gentle :). I have tried the search function but didn’t find an answer.
I have imported a 3D-model into Rhino using 3D-dwg. The model is a residential housing project with 20 simple building volumes we want to use in an external analysis program that needs the building envelope as lines/plines instead of “real” 3D solids or surfaces. I’ve played with ExctractMeshEdges which works as long as I perform the action individually on the building volumes. I can’t find a way perform this action for all the buildings simultaneosly. Is it possible and if so how?

I group the created edges (lines) in Rhino but when I open up the model in Autocad they are not grouped and it’s a plentiful work to manually group the lines for each building volume. Is there a way to group the lines in Rhino so that they remain grouped in Autocad?

I will start learning more about Rhino and also Grasshoper since my BIM-program of taste is connecting quite heavily into Rhino.

Cheers,
Mats

2

If the buildings are at the same (or ‘compatible’) elevation, you could try to make a mesh plane at an elevation that cuts through all and then run the MeshIntersect command to get the plines.

I have no idea about the AutoCAD question. You could perhaps try to turn the lines into one single block first…

3

So the imported buildings are mesh and not NURBS geometry? If so you should be able to select all the mesh buildings, and choose Join, which will join them into one “disjoint” mesh. Then ExtractMeshEdges should work on all of them simultaneously.

However I don’t believe DXF/DWG export preserves grouping… Making the objects into blocks do seem to keep them together though.

–Mitch

4

Hi Mats - does ExtractWireframe get you the lines you need?

-Pascal