blender-plugin-dev_skill

Overview

This skill develops, debug-asserts, and upgrades Blender add-ons and bpy scripts with explicit compatibility for Blender 4.x and 5.x. It scaffolds new add-ons, migrates deprecated API usage, and validates registration and runtime behavior to prevent version breakages. The focus is on pragmatic, compatibility-safe code that runs across the target Blender range.

How this skill works

I inspect the requested behavior, target Blender versions, and existing code to decide whether to produce a full add-on package, a standalone bpy script, or a migration patch. Code output uses a composable file layout (operators.py, ui.py, compat.py, __init__.py), includes version guards or wrappers, and is validated with static Python compilation and optional headless Blender smoke tests. I avoid deprecated or removed APIs and follow explicit compatibility rules to minimize future breakage.

When to use it

• Creating a new Blender add-on compatible with Blender 4.x and 5.x
• Migrating existing add-ons to remove Blender 5.0 deprecations and breakages
• Scaffolding operators, panels, and registration stubs for a feature request
• Resolving runtime errors caused by Blender API changes between 4.x and 5.x
• Validating register/unregister order, bl_idname formats, and operator polls before release

Best practices

• Scope Blender version range up front; default to >= 4.0 with 5.x awareness
• Generate small, composable files: operators.py, ui.py, compat.py, __init__.py
• Encapsulate version differences in compat.py rather than sprinkling bpy.app.version checks
• Run python -m py_compile and headless Blender smoke tests when binaries are available
• Use idempotent register/unregister and unregister classes in reverse order
• Avoid deprecated APIs (scene.use_nodes, dict-like RNA access, bl_ui_utils, bgl) and prefer gpu and AssetRepresentation

Example use cases

• Scaffold a new add-on package and implement a custom operator and panel with 4/5 compatibility
• Patch an add-on to replace removed API calls and provide compat shims in compat.py
• Create a standalone bpy migration script that updates data-access patterns for Blender 5.0
• Debug an operator failing registration under Blender 5.x and produce corrected code with proper bl_idname and poll() checks
• Add GPU drawing migration from bgl to gpu and validate in headless smoke tests