Engine Export Presets

Trigger

Use this skill when the user:

• Needs a Unity, Godot, or Unreal export from Blender Python
• Mentions Y-up, Z-up, centimeter scale, export_yup, axis_forward, or axis_up
• Is about to pass FBX axis kwargs to bpy.ops.export_scene.gltf
• Wants a headless preset the later ai-asset-pipeline-template can call

This skill is the export layer. It composes ai-mesh-cleanup (apply transforms, units), depsgraph-and-evaluated-data (export_apply ships evaluated mesh), and the unapplied-scale-gltf witness (export_apply does not bake object scale). It does not generate meshes.

The core misunderstanding

glTF and FBX do not share axis RNA. bpy.ops.export_scene.gltf has export_yup (boolean, "+Y Up"). It does not have axis_forward or axis_up. bpy.ops.export_scene.fbx has axis_forward and axis_up (axis enums) and global_scale. It does not have export_yup. Passing the other exporter's kwargs is a TypeError or a silent no-op depending on how the call is built.

That split is the contract. Verified on current RNA: