Creating simple 2 flight staircase through grasshopper

It is not even 24 hours since I’ve started playing around with grasshopper3d, I wish to make a 2 flight staircase as shown in the attached file. But I absolutely have no idea how to even start it. Thanks

I would start by creating a horizontal line that goes from the start of the first step to the end of the last. You then divide this line into N equal segments. This can be done via the Divide Curve component, followed by Polyline, followed by Explode Curve.

You then have to start moving each successive line segment up by the same amount. This means generating a list of numbers \left(0, 1, 2, 3, ... \right) using the Series component, and then multiplying each number in that list by the step elevation. Alternatively, if you have a fixed vertical difference for the entire stair, then maybe it’s easier to use the Range component instead.

Once you have your increasing numbers, use them to generate z axis vectors, and use those vectors to Move all your line segments upwards.

You now have the horizontal parts of the steps. You can create the vertical parts easily using the Connect Curves component. Just pick position blending instead of curvature, and make sure you do not close the loop. This gives you the vertical parts of each step already joined to the horizontal ones.

The next step (if you pardon the pun) will be to get the end points of your zig-zag curve and create vertical line segments using Line SDL pointing downward. The length of these will depend on the thickness of the slab you’re looking for.

Finally, join the vertical segments to the zigzag curve, find the end-points again and connect them with a line. You now have the cross section of the stair, which is the hardest part.

All that remains is to extrude and cap that curve to give you breps.


It took me awhile to figure it out but I did it anyway. I think I will be able to figure out how to make a landing and the 2nd flight of stair is now easy thanks to you.
Thank you

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Hi, I tried to follow your solution and the script that [Nihalhgalathia] made but for some reason I get some weird looking stairs. Can you check to see what’s wrong?
Thanks a lot.

stair (15.0 KB) stair test.3dm (7.3 MB)

Some help please?
Thank you!

Try this

stair (9.9 KB)

This works perfect, thanks a lot!