blender-modeling

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---
name: blender-modeling
description: Create and edit 3D meshes in Blender — primitives, hard-surface modeling, mesh operators, modifier stacks (Bevel, Subdivision, Boolean, Mirror, Array, Solidify), bmesh-level edits, retopology basics. Use whenever the user asks to "make/model/create/build a 3D object", "shape/sculpt this", "add a cube/sphere/cylinder/etc.", "extrude/inset/bevel this face", "add a modifier", or any geometry-creation request that isn't a wireframe trace. Make sure to use this skill even if the user does not say "model" — also covers "make a sword", "build a chair", "add a door", "carve out a hole". Pairs with blender-materials for look-dev and blender-pro-workflow for full pipelines.
when_to_use: Any geometry creation, mesh edit, or modifier stack work in Blender. Not for wireframe → 3D conversion (use wireframe-to-3d) and not for sculpting strokes (Blender's sculpt mode is gestural, not text-driven).
allowed-tools: Read Bash mcp__blender__execute_blender_code mcp__blender__get_scene_info mcp__blender__get_object_info
---

# Blender Modeling

Create geometry in Blender via natural language. You emit Python code that the Blender MCP executes; the patterns below cover the common 80%.

## Decision tree

```
What kind of geometry?
├── Hard-surface (vehicles, weapons, architecture, props)
│   → Cube primitive + Bevel + SubSurf modifier stack
│   → See "Hard-surface stack" recipe
│
├── Organic (characters, creatures, plants — block-out only)
│   → Ico Sphere + sculpting (or Voxel Remesh for shape)
│   → For sculpting strokes, redirect: it's gestural, not text-driven
│
├── Architectural / repeating (fences, columns, tile)
│   → Plane/Cube + Array modifier (+ Curve modifier for paths)
│   → See "Array along curve" recipe
│
├── Cylindrical (pipes, columns, bottles)
│   → Cylinder primitive, or Curve + bevel_object
│   → See "Sweep along path" — covered in wireframe-to-3d if needed
│
├── Holes / cuts in existing geometry
│   → Boolean modifier (DIFFERENCE)
│   → See "Boolean cut" recipe
│
└── Quick block-out from primitives only
    → Multiple primitive_*_add calls
    → See "Block-out scene" recipe
```

## Code-execution rules (recap)

- Each `mcp__blender__execute_blender_code` call gets a fresh Python namespace. Re-import everything; identify objects by `bpy.data.objects['name']`.
- Always name objects with `GEO-` prefix. Never leave `Cube.027`.
- Print structured output back so you can parse results.
- Chunk long sequences into multiple calls.

## Recipes

### Critical: axis orientation for elongated objects

For any **elongated/asymmetric** subject (sword blade, knife, bottle, plank, bone, screwdriver tip, etc.), three axes have **different meaning**:

- **Long axis** — the length of the object (78cm for a sword blade)
- **Broad axis** — the wider face axis, what's visible from the "useful" viewing angle (4.5cm for a blade — the flat side you'd lay on a table)
- **Thin axis** — the narrower cross-section axis (0.8cm for a blade — the cutting edge)

**Always orient elongated objects so the broad axis faces the camera in hero shots.** A sword viewed edge-on (camera looking down the thin axis) renders as a thin pole and looks nothing like a sword. The recipes below use this convention:

| Convention | X (left-right of object's local space) | Y (front-back of object's local space) | Z (up-down) |
|------------|---------------------------------------|---------------------------------------|-------------|
| Sword blade | thin (0.8cm) | broad (4.5cm) | long (78cm) — vertical |
| Knife blade | thin | broad | long — horizontal |
| Plank | thin | broad | long |
| Bottle | symmetric (radius) | symmetric (radius) | long (height) |

After building, **rotate the object** so the broad axis points roughly toward the camera. For a sword standing upright with camera in front (camera in -Y direction): rotate the blade 90° around Z so its local Y (broad) → world X, then the broad face is visible from the camera's perspective.

###