Array geometry along group of curves with specific spacing

Hi Folks, First time forum post for me here:

I’m wondering if anyone might know how I might be able to array geometry along a group of curves with a specific spacing in Grasshopper. I’ve created a group of curves by offsetting one curve using a ‘Series’ component for the offset’s distance. This group of curves is then trimmed to account for aisle pathways. The result is a single ‘Crv’ component that represents a dozen or so curves (see attached Screenshot).

I’m hoping to be able to array a theatre seat geometry along these curves, spaced every 22", resulting in something similar to the attached image named “Arrayed Seats” which I manually created outside of Grasshopper. Any help will be MUCH appreciated!


Of course: are you looking for something like this? (4.1 KB)

Is your seat a block, though? If that’s the case, you’ll need to either explode it and use a Bounding Box component with the Union Box option, or find a way to import it in Grasshopper. I recall there was an add-on that would allow this but I cannot remember its name.

I’m sorry, I read your post again and I think this will be more suited to what you’re asking. (9.6 KB)

Thanks Pietro! I really appreciate you taking the time to show me this and it seems like it’s on the right path to accomplishing my goal.

I wasn’t able to fully open your v.2 file. I’ve attached the errors I got, which might have to do with running a different version of Grasshopper (I’m using Rhino5 by the way). Let me know if you have ideas how to overcome the error messages.


Oh yeah, I’m on v6. I’m not sure how to solve that at the moment. Anyway, here’s an image of the algorithm, hope it suffices.

Thanks for the screenshot. For some reason, the multiplication and subtraction components didn’t load, but I was just able to bring them in myself and connect them how your show them. This looks great!

Yes because difference in rh5 and rh6. They changed (variable amount of inputs etc) so if you open a gh 1 file in gh 0.9 they won’t get recognized.

Hi Pietro,
I’ve been able to spend some time with the file you graciously created for me. It is SOOOO close to accomplishing what I was hoping for.

There is a problem or two that I’m experiencing. It seems the algorithm only works with certain curve lengths. If you have a moment, could you take a look at the two attached files and let me know what you think? I put some notes within the GH file.

Thanks again for your help! I NEVER would have figured this out on my own. (13.2 KB)
Theatre Seating (82.8 KB)

Hey Erik,
I’m sorry, I must have been completely drunk the first time I did that algorithm. Luckily the fix should be very simple and straightforward: locate the Round component and use the Floor output instead of the Nearest. In pictures:

This works on the simple algorithm and should work also in the more complex one, but I only manage to take a quick look at that one. Let me know if anything else arises, and remember to “Reply” to my messages or I won’t see the notification! :slight_smile:

Hey Pietro, YES! Making that small change with the “Round” component was definitely the fix! I still have one bizarre problem in my file, in the back of the room, where your seating algorithm isn’t working on all of the curves for some reason. I tried to study where things are going wrong and it seems that the “Shatter” component isn’t dividing the arcs into smaller segments. I’ve simplified the attached version of my file to isolate this specific problem for you, if you have a moment to look at it. Hopefully we can figure out this last (but important) thing and I’ll owe you a big one!

Theatre Seating (30.9 KB)Theatre Seating v.4.3dm (596.3 KB)

Hey Erik, unfortunately I won’t be able to take a look at it until sometime next week! I’ll get back to you asap!

OMG!!! Emerson’s little thing worked! Now everything works. What an awesome GH community! What can I do to ever repay ya’ll??

Check out the results (100% parametric):

Pietro, Just want to make sure you saw my other post, in case you didn’t get a notification. Beautiful!!! Thank you so much!

Saw it just now Erik, great work! :v: