GN Node - Subdivide Single Axis
Image basically explains it.
The current GN subdivision node applies to all axes. It would be of great benefit if if could apply to only one axis.
Image basically explains it.
The current GN subdivision node applies to all axes. It would be of great benefit if if could apply to only one axis.
8 Comments
Imo a generalised bisect / cross-section / edge loop node would be a better implementation of this. UVW picking can get challenging based on topology
I'm sure there are several ways it could be implemented, possibly better than my basic suggestion - so, definitely in favor "improved", even if not a specific UVW approach. My main thought was - at the most basic level, I'm not looking to make a selection of anything. I just want an object split on a single axis, instead of all of them.
Calling it subdivide is kinda wrong and confuses people (you probably should just edit and rename proposal, title changes are allowed), but I fully support some kind of local axis oriented "slice" or "bisect" functionality.
[EDIT: The idea improved the implementation since] This is just not possible. There isn't a single way that would work universally on every topology, and even for those, there are many problems.
You see, a subdivision does not slice a mesh on "each axis", it does 3 things : divide every edges in 2 ; add a vertex in the center of every face; slice every face by joining every new vertex.
Now apply that to every kind of topology and it's gonna work. Either freeform topology, voxel topology, triangulated meshes, ngon soups and even meshes with no faces.
If your proposal is to "limit the cuts" a subdivision does, then what happens if you apply it on a mesh where a face loop intersects with itself?
Does it just stop and create an ngon?
What if there are triangles on your mesh? Does it go left or right? does it just stop? discard the operation because of a single polygon?
Where does the W axis even begin? Does it compute a pathfinding operation to detect the first face loop that circles around itself... for every face in the mesh?!
Even though you can go in edit mode, make a loop cut on every face of a cube and get exactly (topology-wise) what the subdivision operation would give you, the two processes are different.
Look, I don't want to sound mean, and I'm sorry if I did, but geometry nodes are not meant to function like a plugin, where you'd get automatic solutions for common use cases and little to no parameters (I mean the UV nodes are pretty much that but whatever).
Treat them more like extremely powerful primitives that can all work together to push the boundaries of what's possible to create procedurally.
What you propose is indeed simple, but its very "automatic" and very poorly adapts to more examples.
I think OP is looking for a 'single dimension slice' and not a subdivision- which is probably why it's getting downvoted. I agree, there's no such thing as a 'single axis subdivision' because that's not how subdivision works. I think what OP is asking for is a GN node that does what hardops Dice operator does: hardops-manual.readthedocs.io/en/latest/dice/
In Modo there was a tool called "Julienne" that did the same thing: youtube.com/watch
Given that hOPs Dice is destructive, I agree that it would be useful as a node.
Thanks for seeing the trees, as well as the forest.
Yes - to be clear, I'm not asking for a refined version of catmull clark subdivision that magically determines all solutions for all geometry, and uses some undiscovered algorithm to create a loop cut where none logically exists.
I thought the image made the desired end result obvious, but apparently not.
Nodes can already determine the XYZ direction. I'd like to be able to subdivide - sorry, ADD SLICES OF EDGES... using that input data.
Would it work in every situation, every overly dirty mesh with tons of bad topology, boolean disaster input, or a scanned import with 10,000,000 faces? Probably not... so, don't use the node?
Heck, blender's own native loop select tool fails on occasion to select an obvious loop. That doesn't mean we don't like having the tool for all the times it DOES work fine.
From one modo refugee to another (probably), i would like that "procedural slice" too.
i do it by GN but really bad efficent.beause i use some way to boolean and cut the mesh.
why need this GN Tool because need to bend by one axis so i need more mesh loop.