Merge overlapping surfaces




I have a bunch of planar surfaces which are overlapping, and I would like to join them so that those overlapping surfaces become one surface for the purpose of area calculation.

PolySurface.ByJoinedSurfaces does not seem to work, as a Surface.Area node connected to it then takes into account the overlapping surface areas as they were before joining.

So, how can I ensure that the area is calculated only for a flat single planar surface?


Dynamo can only union solid geometry out of the box. One common workaround is to extrude the surfaces into solids, use the “Solid.ByUnion” node and then intersect the base with a plane to get the merged surface. As you can imagine, that can be a bit slow if you’re handling a large amount of objects.


Ah, I was hoping I wouldn’t have to do that. But it worked, and wasn’t so bad. Thanks!