Blender Game Skills

---
name: blender-image-to-3d
description: Build a game-ready 3D asset in Blender from reference images (concept art, photos, turnarounds, sketches, screenshots) for any category, including characters, creatures, architecture, vehicles, props, weapons and environment pieces, through gated phases with rendered evidence compared against the reference. Use this whenever a user supplies or mentions a reference image and wants a 3D model or game asset made from it (modelled, blocked out, sculpted, retopologised, textured, rigged, animated or exported for a game engine), even when Blender is not named. Includes bpy scripts for scene calibration, review renders matched to the reference camera, silhouette measurement, validation, baking, GLB/FBX export with manifests, and clean reimport.
license: MIT
---

# Blender image to 3D

Turn one or more reference images into a delivered game asset by moving through gated phases.
Every gate is passed with rendered evidence compared to the reference from the same camera and
at gameplay pixel size, never by looking at the viewport and deciding it seems fine. Most wasted
work in this pipeline is detail added on top of wrong proportions, so nothing gets detail until
its silhouette passes.

"Perfect" here has a definition: the acceptance checklist in
`references/delivery-and-acceptance.md` passes, the compare sheets show no measured deviation
above the phase tolerance, and every dimension or side that the reference did not show is listed
as inferred. Say so when a single image forces inference; do not present a guessed back as fact.

## Runtime

- Blender 4.2 or newer (used through 5.2), run headless: `blender --background --python <script> -- <args>`.
  Blender 5.x changed several APIs these builds touch; `references/blender-5-notes.md` lists them
  with runtime, baking and review lessons.
  Resolve the binary once: `$BLENDER_BIN`, then `blender` on PATH, then
  `/Applications/Blender.app/Contents/MacOS/Blender`. Workbench renders need no GPU on macOS or
  Windows; on a headless Linux box without a GPU, pass `--engine cycles` to review_render.py.
- A live Blender session through an MCP server (execute-Python tool) is optional and useful for
  inspection. Even then, build through the numbered scripts and save the same master file, so the
  build stays reproducible. In a live session, `exec(open(path).read())` a script and call its
  functions instead of the command line.
- All modelling is written as bpy code in `<asset>/build/NN_<phase>.py`, copied from
  `assets/build_template.py`. Each script opens the master, deletes what it owns, rebuilds it,
  saves. Rerunning any phase is safe. Constants are measured metres with a comment naming the
  reference view they came from, or `# inferred`.
- Skill scripts (all take `-- --help`):

| Script | Purpose |
| --- | --- |
| `scripts/init_master.py` | master .blend: units, collections, calibration proxies, reference planes at real scale, game camera |
| `scripts/review_render.py` | clay / silhouette / wire / checker / material renders from fixed views, the reference-matched camera, gameplay pixel size, turntables, posed frames |
| `scripts/compose_review.py` | compare sheet (reference, render, overlay, gameplay strip) plus silhouette IoU and width-profile numbers; plain Python with Pillow |
| `scripts/world_gate.py` | world-registered silhouette IoU for orthographic reference views: the camera covers the reference matte's exact world window, so scale and placement errors count |
| `scripts/validate.py` | topology, transforms, UVs, weights, armature, sockets, colliders, naming, tri budget; exit 1 on FAIL |
| `scripts/bake_maps.py` | normal and AO from HIGH to LOW, base colour, roughness, metallic; rebuilds delivery materials |