engine-export-presetslisted

# 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: - glTF: https://docs.blender.org/api/current/bpy.ops.export_scene.html#bpy.ops.export_scene.gltf (`export_yup`, no axis enums) - FBX: https://docs.blender.org/api/current/bpy.ops.export_scene.html#bpy.ops.export_scene.fbx (`axis_forward`, `axis_up`, `global_scale`) ## Shared prelude Before any preset: meters in the scene (`scale_length == 1.0`), identity object scale via `transform_apply` through `temp_over