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Author a Blender Character Test Case

Scaffold a new asset-generation test case of asset_kind = "blender-character" — the first Blender-authored skinned character kind: the model builds a rigged, animated, skinned character in headless Blender (bpy) by editing a starter build.py and running tcab-blend, which emits a skinned glTF (character.glb) + preview model.png. This is the short version; Authoring a Blender Character Test Case covers it in full, and Manifests is the authoritative schema.

Its closest relative is the CSG Author a Skinned Character Test Case — same glTF product, from a signed-distance field rather than a real character pipeline. Choose blender-character when the subject needs real topology, a hand-built armature, or IK the CSG kinds cannot express.

Layout

Section titled “Layout”

A version lives at test-cases/<type>/<difficulty>/<slug>/<version>/ and is immutable once runs reference it — revise by adding a new version, not by editing a published one.

test-cases/<type>/<difficulty>/<slug>/<version>/
  test-case.toml         # manifest: type, asset_kind, [voxel], [tool], [output], [model], the overall domain
  variants/              # one standalone TOML file per variant (listed in `variants`)
  prompt.hbs             # rendered into the harness instruction (NOT seeded)
  description.md, README.md  # site blurb + human overview (NOT seeded)
  specs/brief.md         # the character + how the tool behaves — SEEDED
  specs/build.py         # the starter Blender script the model edits — SEEDED (a [[spec]])

A run also gets headless Blender + tcab-blend on PATH and a seeded blender.config.json (bounds, the +Z-up/facing--Y axes, output paths, animation names). There is no target model — the skeleton and binding are the model’s to invent; character.glb and model.png are core-emitted, never in the manifest.

Steps

Section titled “Steps”
  1. Pick a catalog slug (flagship: siege-rifleman), the character, and a version (vX.Y.Z). Choose a body whose credibility rests on real topology and rigging, readable at the bounding box from silhouette and palette alone.
  2. Write specs/brief.md: silhouette/proportions/orientation (built +Z up, facing -Y; warn against pre-rotating to +Y-up), gear baked into the mesh, the exact opaque #rrggbb palette, the weapon_socket rule (an empty hand-parented bone with no vertex influence — the model does not model the weapon), each required animation and how it reads as continuous-skin deformation, and that all authoring is via build.py + tcab-blend. Keep it self-contained.
  3. Write specs/build.py: a runnable-shaped, well-commented starter that loads blender.config.json, clears the scene, and leaves TODOs for build_body_mesh(), build_armature() (incl. weapon_socket), bind_skin_weights(), and author_animation(name) — ending by calling tcab_blend_export.export(config).
  4. Write prompt.hbs using only the documented template variables ({{variant.*}}, {{#each specs}}; it renders in strict mode), pointing at the brief and build.py and stating the hard rules (build/rig only through Blender; bake the gear; keep weapon_socket empty; author every animation; run tcab-blend before returning).
  5. Write test-case.toml: metadata, type = "asset-generation", asset_kind = "blender-character", a variants list, [voxel] (bounding box + background), [tool] (binary = "tcab-blend", preview = "model.png" — a single file, no {part} token), [output] (actions = "build.py" — the recorded trace, re-run for provenance), [model] fixing only the required animations via [[model.animation]] (identity alone — no bones/joints/weights), the seeded brief and starter build.py as two [[spec]]s, and the single overall [[domain]] (an asset-generation case declares no [[review_item]] checklist). Declare no [[reference]], [build], [[check]], or per-kind [canvas]/[sheet]/[ui]/[material]/[particle]/[audio].
  6. Write the non-seeded description.md and README.md.

Read the full guide before you start. The worked example is the flagship siege-rifleman.

Validate

Section titled “Validate”

For every variant:

Terminal window
tcab prompt --test-case <slug> --version <version> --variant <variant>
tcab seed   --test-case <slug> --version <version> --variant <variant>

prompt catches strict-mode template and manifest errors (a stray {part} on preview/actions, a missing required table); seed writes the seeded repository so you can confirm the brief, build.py, and blender.config.json are self-contained.

Next steps

Section titled “Next steps”