Blender-Spine IO (THE FIRST RELEASE!!!)

Release v0.0.1 of Blender-Spine-IO

Open-source Spine 4.3 JSON Exporter for Blender (OCA/OCO-friendly)
Author: Simon Heggie • Status: Alpha • Blender: 4.2+ • Spine: 4.3.39-beta • License: GPL-3.0

Overview

Blender-Spine-IO is an experimental open-source exporter that converts Blender rigs, meshes, UVs, materials, and animations into valid Spine 4.3 JSON.
It supports complex deformation meshes, OCA/OCO pipelines, and automatic Spine blend-modes.
Importer functionality will be added in future versions.

Installation

Extensions (recommended):
Blender → Edit → Preferences → Extensions → Install ZIP → Enable Blender-Spine-IO

Legacy Add-on:
Preferences → Add-ons → Install… → Enable Spine-IO

Where It Appears

File → Export → Spine (.json) — full export dialog

3D Viewport → Sidebar → Spine-IO tab

Quick Export (remembers last path)

Texture Export toggle

Blend-Mode Manager (Normal, Add/Screen, Multiply, Luminosity)

Features (Working in v0.1 Alpha)

✔ Mesh Export

Supports tris, quads, ngons (auto-triangulated)

Internal edges supported (Spine-compatible encoding)

Correct hull detection

Works on weighted and unweighted meshes

✔ Armature & Bones

Full hierarchy export

Proper bone lengths

Accurate local rig-space transforms

Optional auto-scale or constant scale

✔ Weights

Up to 4 influences per vertex

Auto fallback bones

Correct Spine-space coordinates

✔ Animation (FK)

Exports the active Action

Creates Spine-compatible timelines

✔ Materials → Spine Blend Modes

Auto-generated procedural BLEND-MODE node with export of:
normal, additive, multiply, screen

✔ Tools / UI

One-click Quick Export

Blend-mode syncing via background timer

Simple material browser inside Spine-IO tab

✔ OCA/OCO Image Pathing

Removes .OCA/ wrappers

Normalizes nested subfolders

Predictable, stable Blender → Spine texture mapping

✔ Parenting Fix

Unparented weighted meshes automatically bind to correct bones.

Current Issues

⚠ Occasional UI slowdown

Blend-mode sync timer scans materials too often. Needs throttle/caching.

⚠ Root-Bone 90° Rig Hack

Exporter still needs a world-space rotation patch.
Users must keep a zeroed, world-centre root bone.
A correct world→Spine transform is planned.

⚠ FK-only animation

IK/constraints coming later.

⚠ Unweighted meshes

Currently appear at origin unless weighted.

Roadmap

🔥 High Priority

Proper world→Spine transform (remove 90° hack)

Non-deforming controller bones

Drivers (e.g., bone-driven alpha)

IK & constraints support

🔥 Medium Priority

Multi-Action → multi-animation export

Skins + slot colour/dark-colour

2-colour tint

PSD/Krita layer-name → slot auto-mapping

🔥 Low Priority

Full Spine → Blender importer

Multi-rig UI merging

Export presets (Godot / Armory / Unity)