Creating outerlines

I need to get the outerlines of my prefab…

We want to make floors out of our prefab.

So far i have got the faces, but how to get the outerlines or outer points so we can create the lines to create the floors with


Why not use the top surface instead?

Filter for the horizontal up surfaces, get the perimeter curves, group by curve loop (GroupCurves node from Archi-Lab), create a polycurve, make a new surface by the patch, filter to get the surface with the largest area, and pull those perimeter curves.

Another option would be to project the whole geometry onto a plane, and use the that as your perimeter curves. Not sure which would be faster.

I typically grab the center point of each surface, sort them by the z-values, and then grab the last item from the list. After that, just do what has already been suggested with perimeter curves.

If you are dealing with sloped slabs, you will have to sample multiple points on each surface (since the highest face can return and edge) and average out the sample z-values.

Not all surfaces are horizontal… some are on an angle, so then it is hard to sort which are on an angle and which are vertical… then i also need to sort the boundary lines and see if they have the same x and y…

also got a problem with some elements which don’t even give me the faces… get an error on those…