custom-propertieslisted

# Custom Properties ## Trigger Use this skill when the user: - Wants to attach data to objects, scenes, or other Blender datablocks that survives save and load - Mentions `bpy.props`, `PropertyGroup`, `PointerProperty`, "custom properties" - Is unsure where to store add-on settings - Sees a deprecation warning about property assignment ## Required inputs - **What you want to store**: a single number, a small struct, a list of items, or a complex hierarchy - **Where it should live**: Scene (per-document), Object (per-object), WindowManager (session-only), AddonPreferences (per-user) - **Whether it must persist** through save/load (almost always yes) ## The type annotation form (mandatory since 2.8) ```python import bpy class MY_ADDON_PG_settings(bpy.types.PropertyGroup): intensity: bpy.props.FloatProperty( name="Intensity", description="How strong the effect is", default=1.0, min=0.0, max=10.0, ) use_smoothing: bpy.props.BoolProperty(name="Smooth", default=True) mode: bpy.props.EnumProperty( name="Mode", items=[ ('FAST', "Fast", "Lower quality, faster"), ('GOOD', "Good", "Balanced"), ('BEST', "Best", "Best quality, slower"), ], default='GOOD', ) ``` The properties are declared with `:` (PEP 526 annotations), not `=` (assignment). Blender's metaclass scans the annotation namespace and registers each `bpy.props.*` it finds. The assignment for