Unroll spiral stair

Hi everyone!

I’m trying to do something similar posted here http://dynamobim.org/forums/topic/flow-along-surface/ . In my case I want to unroll de section lines between a spiral stair and a cylinder… but I can’t realize it… the stairs are made by several flights no continuos (1cm gap) because is a precast stair. So I got about 20 surfaces as result to intersect the cylinder with stairs, so I’m trying to unroll the edges to get a circular unfold section projecting the curves on a planar surface (wich is the cylinder 2.855m radius unfold). Hhere the .dyn https://drive.google.com/file/d/0B0l8DNpUDrjIM0hkRnpYV3RQQnc/view?usp=sharing. Also some captures


Hi @Miguel_Angel

You need to drop revit file also. Thanks :slight_smile:

True @Kulkul https://drive.google.com/open?id=0B0l8DNpUDrjIcjBfamx5VkIzVms here it is!


Hi @Miguel_Angel
When I try and do it on all the stairs it looks like this :

I’ts because the stairs revolve around a cylinder…

I would suggest you do it with one run/landing, then copy paste it as many times as you need:

here’s the .dyn : unfold stairs.dyn (19.8 KB)


Great help on this one ! Had the same problem, solved now ! Thanks

1 Like

Hi !
This topic is very interesting. Thank you all for sharing your expirence !
I have a similar case but I’ve a stair modeled with a Generic Model, how may I work it out ?

Thanks !