# Mocking up a small circular city layout with Geometry Nodes

It is my first time using GN. I am in a draft phase of a project, and I thought to learn GN in this specific project. I believe it will enable me to have a more flexible process.

I want to mock up a small city on a thickened disk; the main goal is to find a modular grid to place my buildings. I am not aiming to build the scene in GN but to find how many blocks I should use, so this is just for me to draft the right proportions, and then I will jump to model everything the "old school" way.

Summing up: I want a flat cylinder (my city land), and I want to create from that cylinder an outer ring to boolean a grid, working as streets, that I can scale up or down.

I started by myself, just searching for nodes and googling a bit:

Above, you can see the ring and node setup. Then I will Join the Center disk to make it visible and use the ring as the boolean of the streets/grid.

I added a subdivision just to check that my mesh is closed, preparing it for the boolean phase. I added a merge to distance, but I can see the subdivision node keeps reading the mesh as two separate entities. I am sure I miss some kind of node before my merge to distance.

Can you help me to figure it out?

Also, I would like to keep this post open to ask coming doubts when I lay my streets on the cylinder. Do I need to create a new post, or can I keep expanding this?

Thank you

• Regarding your additional question: Please be so kind and always create new posts if further questions arise that do not exactly correspond to the title of this post. Only in this way it is possible to give precise answers here and it allows others to find the post via the search function if they have similar problems. A title of a question should therefore also always apply exactly to a single concrete problem, so that it is clear from it what the question is about. Therefore, always keep the topics strictly separated from each other, because this creates clarity. Thank you! Oct 10, 2022 at 9:19

• @BrunoSuraski I'm not sure what you mean by "make it work" - if nearby vertices aren't merged, perhaps they don't have exact same coordinates and you need to set a small number like 0.001 as the distance. Oct 8, 2022 at 10:07
• Tip: You could also use the node Quadrilateral instead of Curve Circle as profile here. This would allow you to define the dimensions more precisely/understandably. Oct 8, 2022 at 13:35