name	Procedural Mesh Generation (Blender bpy)
description	Generate 3D meshes for ZX games using Blender bpy in headless mode. Triggers: "generate mesh", "3D model", "low-poly", "blender script", "hard surface", "organic mesh", "metaballs", "UV unwrap", "export glb". Before generating: Check `.studio/visual-style.md` for project style specs. Load references when: - Basic shapes, primitives → `references/bpy-primitives.md` - Modifiers (bevel, mirror, array) → `references/bpy-modifiers.md` - Organic shapes, metaballs, skin → `references/bpy-organic-workflows.md` - UV, normals, cleanup, export → `references/bpy-post-processing.md` - Tangent export for normal maps → `references/bpy-tangent-export.md` - Project structure, multiple assets → `generator-patterns` skill Related skills: - NORMAL MAPS: `procedural-normal-maps` (requires tangent export) - CHARACTERS: `procedural-characters` (extrude+scale paradigm) - TEXTURING: `mesh-texturing-workflows` - ANIMATION: `procedural-animations`
version	1.4.0

Procedural Mesh Generation

Generate game-ready 3D meshes with proper UVs and normals for Nethercore ZX.

Prerequisites

Blender 3.0+ must be installed and in PATH:

blender --version

Run mesh generation via: blender --background --python .studio/generate.py -- --only meshes

Spec-Based Workflow

Write one mesh spec per file under .studio/specs/meshes/:

# .studio/specs/meshes/barrel.spec.py
MESH = {
    "mesh": {
        "name": "barrel",
        "primitive": "cylinder",
        "params": {"radius": 0.45, "depth": 1.1, "vertices": 24},
        "modifiers": [{"type": "bevel", "width": 0.02, "segments": 2}],
        "uv": {"mode": "smart_project", "angle_limit": 66.0},
        "export": {"tangents": True},
    }
}

Generate with:

blender --background --python .studio/generate.py -- --only meshes

Workflow Selection

Mesh Type	Workflow	Reference
Props, weapons, vehicles, architecture	Polygon modeling (primitives + modifiers)	`bpy-primitives.md`, `bpy-modifiers.md`
Blobby shapes (slimes, eggs)	Metaballs	`bpy-organic-workflows.md#metaballs`
Creatures from skeleton	Skin modifier	`bpy-organic-workflows.md#skin-modifier`
Complex smooth blends	SDF pipeline	`bpy-organic-workflows.md#sdf-pipeline`

Hard Surface Quick Reference

Core Primitives:

bpy.ops.mesh.primitive_cube_add() - Crates, boxes
bpy.ops.mesh.primitive_cylinder_add() - Barrels, pillars
bpy.ops.mesh.primitive_uv_sphere_add() - Spheres, domes
bpy.ops.mesh.primitive_cone_add() - Spikes, cones
bpy.ops.mesh.primitive_torus_add() - Rings, wheels

Key Modifiers: MIRROR, BEVEL, SOLIDIFY, ARRAY, BOOLEAN, DECIMATE

See references/bpy-modifiers.md for detailed modifier patterns.

Console Constraints

Use Case	Triangle Budget	Bones (if animated)
Swarm entities	50-150	-
Props	50-300	-
Characters	200-500	16-24
Vehicles	300-800	-
Hero/close-up	500-2000	32-48

Texture resolution: Power-of-2 only (64, 128, 256, 512)

Required Post-Processing

Every mesh MUST have before export:

UV unwrap - smart_project or cube_project
Normals - shade_smooth + use_auto_smooth
Cleanup - remove_doubles, delete_loose
Triangulate - quads_convert_to_tris
Export - GLB with export_normals=True

See references/bpy-post-processing.md for implementation.

File Organization

One mesh spec per file:

.studio/specs/meshes/
├── barrel.spec.py
└── crate.spec.py

generated/meshes/
├── barrel.glb
└── crate.glb

nether.toml Integration

[build]
script = "blender --background --python .studio/generate.py -- --only meshes && cargo build -p game --target wasm32-unknown-unknown --release"

[[assets.meshes]]
id = "barrel"
path = "../generated/meshes/barrel.glb"

Tangent Export (for Normal Maps)

If using normal maps, enable tangents:

mesh.calc_tangents()  # Requires UVs
bpy.ops.export_scene.gltf(
    filepath="output.glb",
    export_tangents=True
)

See references/bpy-tangent-export.md for complete workflow.

Quality Checklist

Triangle count within budget
UVs unwrapped (no overlapping)
Normals consistent (no inverted faces)
No loose geometry
Triangulated
Correct scale (1 unit = 1 meter)
Origin at logical point
Tangents if using normal maps

Procedural Mesh Generation (Blender bpy)

Install Skill

SKILL.md