Tools & setup

Authoring TiedUp! content needs one program (Blender) and two exporters inside it — plus the official rig to start from. Get all three ready once, then never think about it again.

The two-tool split (do not skip this)

Meshes and animations leave Blender through different exporters. This trips up everyone, so it is the first thing to internalise — see Overview for the full pipeline.

Meshes ≠ animations

• Meshes (item & furniture models) → Blender’s built-in File → Export → glTF 2.0 (.glb).
• Animations → the bundled Epic Fight JSON addon (io_scene_minecraft_json), which writes .json clips only.
• The addon never makes a .glb, and the glTF exporter never makes an animation. You use both, for different jobs.

Meshes → .glb

Built-in glTF 2.0 exporter. Ships with Blender — just enable the tick-box.

✅ Available

Animations → EF-JSON

The Epic Fight JSON addon. Install from the bundled folder; you still hand-add the constructor block to each clip. 🔧 Manual / tool-gap

1. Install Blender

Install Blender 2.80 or newer (blender.org). 3.6 LTS, 4.x, and 5.0 all work well — 5.0 is what this project’s author uses day-to-day.

Note

The only hard limit is the lower bound: the addon’s bl_info minimum is 2.80. Older guides that say “2.79 through 5.0+” are wrong on the 2.79 end — those code paths are best-effort legacy and unsupported, so don’t author on 2.79. The high end is unrestricted: 5.0 is fine.

2. Enable the built-in glTF 2.0 exporter (meshes)

This is the exporter that produces your actual item and furniture meshes. It ships with Blender; in most builds it is already on. Confirm it:

1. Edit → Preferences → Add-ons.
2. Search glTF.
3. Tick “Import-Export: glTF 2.0 format” if it isn’t already.
4. Confirm the menu exists: File → Export → glTF 2.0 (.glb/.gltf).

Tip

When you export, choose the .glb (binary) format — it embeds the baked texture inside the file, so there is no separate .png to ship. Author tintable textures in grayscale so a tint_channels colour reads correctly; tint applies to materials named tintable_*. See Textures & tint.

3. Install the Epic Fight JSON addon (animations only)

This addon exports your animation clips as EF-JSON. It is bundled with the mod repo at docs/tools/io_scene_minecraft_json/.

1. Zip the bundled folder so you have io_scene_minecraft_json.zip (or grab the addon ZIP if you have one).
2. Edit → Preferences → Add-ons → Install…, pick the ZIP.
3. Enable the checkbox next to “Epic Fight JSON” — that is the add-on’s display name.
4. Confirm the menus appear:
   • File → Export → Animated Minecraft Model (.json)
   • File → Export → Batch MC Animations (.json)
   • File → Import → Animated Minecraft Model (.json)

The add-on does NOT export meshes

Despite the import/export menu offering an “Export Mesh” tick-box, the mod loads meshes as .glb only (via the built-in glTF exporter, step 2). Treat this add-on as animations + constructor block. Older guides that list it under “export the GLB” or “Required for the mesh” are wrong.

The display name is “Epic Fight JSON”

Older docs call it “Minecraft Model Json Exporter” or “Antikythera blender-json-addon”. In current Blender the enable-checkbox and the add-on panel both read “Epic Fight JSON”. Same add-on, renamed — look for that string.

Don’t trust “Check for Updates” 🔧 Manual / tool-gap

The add-on has a built-in updater, but its “Check for Updates” button points at a different upstream repo (Epic-Fight/blender-json-exporter) than the one the guides reference. It may pull a build that doesn’t match this mod’s expectations.

Caution

Update by hand, not via the in-Blender button: replace the add-on with the docs/tools/io_scene_minecraft_json/ version shipped alongside the mod you’re authoring for. The two tools are versioned together; the auto-updater is not.

Don’t use the “Bedrock Model” exporter

Some Blender builds carry a similarly-named Bedrock Model exporter. It produces a completely different JSON shape and the mod will not load it. Quick sanity check on any clip you export — open it in a text editor:

WRONG  → starts with  "format_version": "1.16.100"
WRONG  → contains an  "animations"  (with an s) object
RIGHT  → top-level    "animation"   (no s, an array)

If you see the Bedrock markers, re-export through Animated Minecraft Model (.json).

4. Get the official rig

Do not rebuild the 20-bone biped by hand. A single mistyped bone name and the renderer silently ignores that joint — the mesh shows up misshapen with no error.

Start from the bundled rig:

docs/tools/EpicFight Animation Rig.blend

1. Open the .blend, then Save As a copy under your item’s name (e.g. my_armbinder.blend).
2. Build your mesh on top of the existing armature — don’t replace it.
3. Weight-paint to the biped bones (see the modeling/skinning notes in the legacy artist guide).
4. (optional) Animate the biped bones for an idle / struggle / pose clip.
5. Export: the mesh as .glb (built-in glTF), the animation as EF-JSON (Epic Fight JSON).

Bone names are load-bearing

The renderer matches your vertex groups to the biped’s 20 bone names. An unmatched group is silently re-bound to Root at skin time — so a typo doesn’t crash, it just collapses that part onto the root. Keep the rig’s bone names exactly as shipped.

5. Animation-export checklist (Epic Fight JSON)

When you export a clip with the add-on, two gotchas are worth a pre-flight check:

Deform-bone filtering & the Root fallback

• The exporter skips bones with Deform disabled — their animation tracks silently vanish from the JSON. If a bone you animated isn’t moving in-game, confirm Bone → Deform is ticked in Blender. (Editing a bundled mesh you didn’t author? Re-check this first.)
• Verts that end up unweighted fall back to ('Root', 1.0) with only a console WARNING — no hard error. Watch the Blender system console on export.

Note

Every exported clip still needs a constructor block hand-added before the mod will register it — the add-on never emits one. That’s covered on Animations.

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Toolchain ready? Walk Your First Item end-to-end. Prefer clicking over editing JSON? There is also an experimental in-game pack editor — enabled by a config flag, off by default.