I am learning to use Geometry Nodes. I have a triangulated grid with corner vertices at $(0, 0, 0)$, $(1, 0, 0)$, $(1, 1, 0)$, and $(0, 1, 0)$. I want to delete all vertices (and faces and edges) above the line $y = 1 − x$. What is the simplest way to do this?
My end-goal is to have a triangle mesh with vertices at $(0, 0, 0)$, $(1, 0, 0)$, and $(0, 1, 0)$, and a user-input integer $n$ greater than or equal to one, with the main triangle subdivided into similar triangles such that:
- each side of the subdivided mesh is composed of $n$ edges, and
- each internal edge is parallel to one of the original three sides (or, equivalently, the internal angles of all new, smaller triangles are identical to the internal angles of the original, larger triangle).
The "Subdivide Mesh" node doesn't do what I want, as it divides each side of the main triangle into $2^n$ edges and divides the triangle itself into quads with internal edges that are not parallel to the boundary edges. I've looked through the other node options and the documentation, but I haven't seen any single node that seems like it will work, so I'm trying to work out the simplest combination that achieves my goal. If there is a better way than my current subdivide-a-grid-and-delete-half-of-it approach, I'd love to see it.
This question has several answers which give node setups that are enormously complicated, with a focus on subdividing arbitrary 3D meshes by powers of two. I just want to subdivide a single flat triangle linearly instead of exponentially.
(X+Y > 1)$\endgroup$