Hello, Im working on a simple castle model. I need to model fences on the roof, but I cant subdivide more than 7 faces inside one square face. How can I fix this? Also, is it possible to subdivide more than one selected face at the same time?
This one is obvious. You’re subdividing individual quadrilateral faces and faces around get turned into n-gons that have more than 4 sides. N-gons can’t be subdivided so that it would create more faces, it subdivides the edges around the perimeter instead.
Look at the top header. It says you have one face selected, yet it has 96 vertices and edges, and triangulating that will produce 604 triangles. You’ve tried to subdivide that n-gon many times.
Yes it’s possible to subdivide more than one face at a time, but what you really want to be doing is cutting in geometry that you need and keeping surrounding geometry manageable at the same time. If you need connected geometry, that means using extrude (E), loop cut and slide (ctrl+R), knife (K) and other tools to manage it.
But fences don’t grow out of roofs, those are separate objects and fixed in place, so probably better to keep them as separate geometry or as separate object. You didn’t list a good reason to make those as connected geometry.
You most certainly can subdivide a quad into as many pieces as you like:
When you’re subdividing for this purpose, make sure you check the “Quad/Tri Mode” box in the operator panel (F6), after the subdivision. The reason it appears that you can’t subdivide is due to the way bmesh handles subdivided ngons. If you switch to vert select mode, you’ll see that the edges were in fact being subdivided, it simply wasn’t connecting edges within the ngons. If you check the “Quad/Tri Mode” box, this will no longer be a problem.
Also, you should absolutely be subdividing all your faces at the same time, so long as you intend for them to have the same number of total subdivisions. You’ll have less cleanup, and will be able to avoid much of the issue you’re currently having.
Anyhow, it’s a simple thing to miss, which can be quite confusing. I personally don’t find any utility in the current paradigm of maintaining ngons, at least by default. For this reason I use Shift+W to subdivide with the Quad/Tri Mode enabled.
Heres the model I try to make: https://www.treatstock.com/3d-printable-models/272-hyrule-castle?fileId=1643
The Hyrule castle from the The Legend Of Zelda - Ocarina Of Time game on Nintendo 64 
It will be a very simple remake of the model (basic cubes).
Good idea, think Ill go for that.
If the goal is to 3D print the thing, might need to connect the geometry, or intersecting (but manifold) geometry if the slicing software supports that. Good thing is that 3D printers don’t care about nice model structures, just that the surfaces clearly define a solid (being error-free, manifold). You could use separate geometry and/or separate objects either way while working for that goal.
If the model is for some other purpose, then the model requirements might be different.
Aight. Too many if’s to my liking. Good luck.
Im not into 3D printing at all 
I just want to remodel this great castle and use it in my Ocarina Of Time remake for UE4. Im aware its done already, but Id like to try it myself. Thanks for your tips all!
