| name | threejs-procedural-vegetation |
| description | Generate authored procedural trees and vegetation in Three.js. Use for trunks, recursive branches, roots, canopies, leaf cards, species presets, growth forces, trellises, deterministic variation, and wind deformation. |
Procedural Vegetation
Represent a plant as a growth hierarchy plus rendering adaptations. Do not model it as randomly scattered cylinders.
Build sequence
- Define a per-level species table: length, radius, taper, child count, emergence range, angle, twist, gnarliness, sections, radial segments.
- Grow branches iteratively from a queue so recursion depth and budgets remain inspectable.
- Emit each branch as oriented rings with an intentional UV seam.
- Update section orientation from:
- inherited direction;
- stochastic curvature;
- tropism or external force;
- optional attraction constraints.
- Spawn children with stratified longitudinal slots and independently permuted angular slots.
- Generate leaves only after branch topology is stable.
- Build foliage normals from both card orientation and local crown volume.
- Choose wind scope explicitly. Leaf-root deformation, branch hierarchy deformation, and whole-tree sway are separate systems.
Read references/structured-ash-growth-system.md and preserve its preset, continuation, child-placement, leaf, material, wind, and composition contracts before tuning.
Read the Ash Growth System implementation
with its authored preset for a
contract-accurate implementation and its diagnostic attributes.
Visual failure conditions
- branches form visible helices;
- every child emerges at the same relative height;
- bark texture scale changes with branch radius;
- leaves reveal flat card normals under rotation;
- leaf wind moves card roots instead of remaining anchored;
- branch wind is claimed to match a reference whose branches are static;
- different seeds change species identity rather than controlled variation;
- geometry cost grows without a per-level budget.
Routing boundary
Use $threejs-procedural-geometry for generic branch-ring emission without a
growth model. This skill owns species tables, topology, child placement,
foliage, roots, and hierarchical wind.
