user: Describe U from the Blender manual or Python API, including usage steps and snippets.

assistant: it.html#bpy.types.ParticleEdit.use_fade_time) - [use_fading (bpy.types.GreasePencilBuildModifier attribute)](bpy.types.GreasePencilBuildModifier.html#bpy.types.GreasePencilBuildModifier.use_fading) - [use_fake_user (bpy.types.ID attribute)](bpy.types.ID.html#bpy.types.ID.use_fake_user) - [use_fallback_value (bpy.types.DriverTarget attribute)](bpy.types.DriverTarget.html#bpy.types.DriverTarget.use_fallback_value) - [use_falloff_uniform (bpy.types.GreasePencilHookModifier attribute)](bpy.types.GreasePencilHookModifier.html#bpy.types.GreasePencilHookModifier.use_falloff_uniform)   - [(bpy.types.HookModifier attribute)](bpy.types.HookModifier.html#bpy.types.HookModifier.use_falloff_uniform) - [use_fast_edit (bpy.types.TextCurve attribute)](bpy.types.TextCurve.html#bpy.types.TextCurve.use_fast_edit) - [use_fast_gi (bpy.types.SceneEEVEE attribute)](bpy.types.SceneEEVEE.html#bpy.types.SceneEEVEE.use_fast_gi) - [use_fcurve_high_quality_drawing (bpy.types.PreferencesEdit attribute)](bpy.types.PreferencesEdit.html#bpy.types.PreferencesEdit.use_fcurve_high_quality_drawing) - [use_file_compression (bpy.types.PreferencesFilePaths attribute)](bpy.types.PreferencesFilePaths.html#bpy.types.PreferencesFilePaths.use_file_compression) - [use_file_extension (bpy.types.RenderSettings attribute)](bpy.types.RenderSettings.html#bpy.types.RenderSettings.use_file_extension) - [use_fill (bpy.types.MaskSpline attribute)](bpy.types.MaskSpline.html#bpy.types.MaskSpline.use_fill) - [use_fill_caps (bpy.types.Curve attribute)](bpy.types.Curve.html#bpy.types.Curve.use_fill_caps) - [use_fill_holdout (bpy.types.MaterialGPencilStyle attribute)](bpy.types.MaterialGPencilStyle.html#bpy.types.MaterialGPencilStyle.use_fill_holdout) - [use_fill_holes (bpy.types.MaskLayer attribute)](bpy.types.MaskLayer.html#bpy.types.MaskLayer.use_fill_holes) - [use_fill_limit (bpy.types.BrushGpencilSettings attribute)](bpy.types.BrushGpencilSettings.html#bpy.types.BrushGpencilSettings.use_fill_limit) - [use_fill_overlap (bpy.types.MaskLayer attribute)](bpy.types.MaskLayer.html#bpy.types.MaskLayer.use_fill_overlap) - [use_filter (bpy.types.FileSelectParams attribute)](bpy.types.FileSelectParams.html#bpy.types.FileSelectParams.use_filter)   - [(bpy.types.SpaceSpreadsheet attribute)](bpy.types.SpaceSpreadsheet.html#bpy.types.SpaceSpreadsheet.use_filter) - [use_filter_asset_only (bpy.types.FileSelectParams attribute)](bpy.types.FileSelectParams.html#bpy.types.FileSelectParams.use_filter_asset_only) - [use_filter_backup (bpy.types.FileSelectParams attribute)](bpy.types.FileSelectParams.html#bpy.types.FileSelectParams.use_filter_backup) - [use_filter_blender (bpy.types.FileSelectParams attribute)](bpy.types.FileSelectParams.html#bpy.types.FileSelectParams.use_filter_blender) - [use_filter_blendid (bpy.types.FileSelectParams attribute)](bpy.types.FileSelectParams.html#bpy.types.FileSelectParams.use_filter_blendid) - [use_filter_brushes_by_tool (bpy.types.PreferencesView attribute)](bpy.types.PreferencesView.html#bpy.types.PreferencesView.use_filter_brushes_by_tool) - [use_filter_by_owner (bpy.types.WorkSpace attribute)](bpy.types.WorkSpace.html#bpy.types.WorkSpace.use_filter_by_owner) - [use_filter_case_sensitive (bpy.types.SpaceOutliner attribute)](bpy.types.SpaceOutliner.html#bpy.types.SpaceOutliner.use_filter_case_sensitive) - [use_filter_children (bpy.types.SpaceOutliner attribute)](bpy.types.SpaceOutliner.html#bpy.types.SpaceOutliner.use_filter_children) - [use_filter_collection (bpy.types.SpaceOutliner attribute)](bpy.types.SpaceOutliner.html#bpy.types.SpaceOutliner.use_filter_collection) - [use_filter_complete (bpy.types.SpaceOutliner attribute)](bpy.types.SpaceOutliner.html#bpy.types.SpaceOutliner.use_filter_complete) - [use_filter_files (bpy.types.PreferencesFilePaths attribute)](bpy.types.PreferencesFilePaths.html#bpy.types.PreferencesFilePaths.use_filter_files) - [use_filter_folder (bpy.types.FileSelectParams attribute)](bpy.types.FileSelectParams.html#bpy.types.FileSelectParams.use_filter_folder) - [use_filter_font (bpy.types.FileSelectParams attribute)](bpy.types.FileSelectParams.html#bpy.types.FileSelectParams.use_filter_font) - [use_filter_id_type (bpy.types.SpaceOutliner attribute)](bpy.types.SpaceOutliner.html#bpy.types.SpaceOutliner.use_filter_id_type) - [use_filter_image (bpy.types.FileSelectParams attribute)](bpy.types.FileSelectParams.html#bpy.types.FileSelectParams.use_filter_image) - [use_filter_invert (bpy.types.DopeSheet attribute)](bpy.types.DopeSheet.html#bpy.types.DopeSheet.use_filter_invert)   - [(bpy.types.UIList attribute)](bpy.types.UIList.html#bpy.types.UIList.use_filter_invert) - [use_filter_lib_override_system (bpy.types.SpaceOutliner attribute)](bpy.types.SpaceOutliner.html#bpy.types.SpaceOutliner.use_filter_lib_override_system) - [use_filter_movie (bpy.types.FileSelectParams attribute)](bpy.types.FileSelectParams.html#bpy.types.FileSelectParams.use_filter_movie) - [use_filter_object (bpy.types.SpaceOutliner attribute)](bpy.types.SpaceOutliner.html#bpy.types.SpaceOutliner.use_filter_object) - [use_filter_object_armature (bpy.types.SpaceOutliner attribute)](bpy.types.SpaceOutliner.html#bpy.types.SpaceOutliner.use_filter_object_armature) - [use_filter_object_camera (bpy.types.SpaceOutliner attribute)](bpy.types.SpaceOutliner.html#bpy.types.SpaceOutliner.use_filter_object_camera) - [use_filter_object_content (bpy.types.SpaceOutliner attribute)](bpy.types.SpaceOutliner.html#bpy.types.SpaceOutliner.use_filter_object_content) - [use_filter_object_empty (bpy.types.SpaceOutliner attribute)](bpy.types.SpaceOutliner.html#bpy.types.SpaceOutliner.use_filter_object_empty) - [use_filter_object_grease_pencil (bpy.types.SpaceOutliner attribute)](bpy.types.SpaceOutliner.html#bpy.types.SpaceOutliner.use_filter_object_grease_pencil) - [use_filter_object_light (bpy.types.SpaceOutliner attribute)](bpy.types.SpaceOutliner.html#bpy.types.SpaceOutliner.use_filter_object_light) - [use_filter_object_mesh (bpy.types.SpaceOutliner attribute)](bpy.types.SpaceOutliner.html#bpy.types.SpaceOutliner.use_filter_object_mesh) - [use_filter_object_others (bpy.types.SpaceOutliner attribute)](bpy.types.SpaceOutliner.html#bpy.types.SpaceOutliner.use_filter_object_others) - [use_filter_script (bpy.types.FileSelectParams attribute)](bpy.types.FileSelectParams.html#bpy.types.FileSelectParams.use_filter_script) - [use_filter_show (bpy.types.UIList attribute)](bpy.types.UIList.html#bpy.types.UIList.use_filter_show) - [use_filter_sort_alpha (bpy.types.UIList attribute)](bpy.types.UIList.html#bpy.types.UIList.use_filter_sort_alpha) - [use_filter_sort_lock (bpy.types.UIList attribute)](bpy.types.UIList.html#bpy.types.UIList.use_filter_sort_lock) - [use_filter_sort_reverse (bpy.types.UIList attribute)](bpy.types.UIList.html#bpy.types.UIList.use_filter_sort_reverse) - [use_filter_sound (bpy.types.FileSelectParams attribute)](bpy.types.FileSelectParams.html#bpy.types.FileSelectParams.use_filter_sound) - [use_filter_text (bpy.types.FileSelectParams attribute)](bpy.types.FileSelectParams.html#bpy.types.FileSelectParams.use_filter_text) - [use_filter_view_layers (bpy.types.SpaceOutliner attribute)](bpy.types.SpaceOutliner.html#bpy.types.SpaceOutliner.use_filter_view_layers) - [use_filter_volume (bpy.types.FileSelectParams attribute)](bpy.types.FileSelectParams.html#bpy.types.FileSelectParams.use_filter_volume) - [use_find_all (bpy.types.SpaceTextEditor attribute)](bpy.types.SpaceTextEditor.html#bpy.types.SpaceTextEditor.use_find_all) - [use_find_wrap (bpy.types.SpaceTextEditor attribute)](bpy.types.SpaceTextEditor.html#bpy.types.SpaceTextEditor.use_find_wrap) - [use_fixed_location (bpy.types.FollowPathConstraint attribute)](bpy.types.FollowPathConstraint.html#bpy.types.FollowPathConstraint.use_fixed_location) - [use_flat_faces (bpy.types.SolidifyModifier attribute)](bpy.types.SolidifyModifier.html#bpy.types.SolidifyModifier.use_flat_faces) - [use_flight (bpy.types.BoidSettings attribute)](bpy.types.BoidSettings.html#bpy.types.BoidSettings.use_flight) - [use_flip_axis (bpy.types.BlendTexture attribute)](bpy.types.BlendTexture.html#bpy.types.BlendTexture.use_flip_axis)   - [(bpy.types.ImageTexture attribute)](bpy.types.ImageTexture.html#bpy.types.ImageTexture.use_flip_axis) - [use_flip_normals (bpy.types.SolidifyModifier attribute)](bpy.types.SolidifyModifier.html#bpy.types.SolidifyModifier.use_flip_normals) - [use_flip_particles (bpy.types.FluidDomainSettings attribute)](bpy.types.FluidDomainSettings.html#bpy.types.FluidDomainSettings.use_flip_particles) - [use_flip_x (bpy.types.CameraBackgroundImage attribute)](bpy.types.CameraBackgroundImage.html#bpy.types.CameraBackgroundImage.use_flip_x)   - [(bpy.types.EffectStrip attribute)](bpy.types.EffectStrip.html#bpy.types.EffectStrip.use_flip_x)   - [(bpy.types.ImageStrip attribute)](bpy.types.ImageStrip.html#bpy.types.ImageStrip.use_flip_x)   - [(bpy.types.MaskStrip attribute)](bpy.types.MaskStrip.html#bpy.types.MaskStrip.use_flip_x)   - [(bpy.types.MetaStrip attribute)](bpy.types.MetaStrip.html#bpy.types.MetaStrip.use_flip_x)   - [(bpy.types.MovieClipStrip attribute)](bpy.types.MovieClipStrip.html#bpy.types.MovieClipStrip.use_flip_x)   - [(bpy.types.MovieStrip attribute)](bpy.types.MovieStrip.html#bpy.types.MovieStrip.use_flip_x)   - [(bpy.types.SceneStrip attribute)](bpy.types.SceneStrip.html#bpy.types.SceneStrip.use_flip_x)   - [(bpy.types.ShaderFxFlip attribute)](bpy.types.ShaderFxFlip.html#bpy.types.ShaderFxFlip.use_flip_x) - [use_flip_y (bpy.types.CameraBackgroundImage attribute)](bpy.types.CameraBackgroundImage.html#bpy.types.CameraBackgroundImage.use_flip_y)   - [(bpy.types.EffectStrip attribute)](bpy.types.EffectStrip.html#bpy.types.EffectStrip.use_flip_y)   - [(bpy.types.ImageStrip attribute)](bpy.types.ImageStrip.html#bpy.types.ImageStrip.use_flip_y)   - [(bpy.types.MaskStrip attribute)](bpy.types.MaskStrip.html#bpy.types.MaskStrip.use_flip_y)   - [(bpy.types.MetaStrip attribute)](bpy.types.MetaStrip.html#bpy.types.MetaStrip.use_flip_y)   - [(bpy.types.MovieClipStrip attribute)](bpy.types.MovieClipStrip.html#bpy.types.MovieClipStrip.use_flip_y)   - [(bpy.types.MovieStrip attribute)](bpy.types.MovieStrip.html#bpy.types.MovieStrip.use_flip_y)   - [(bpy.types.SceneStrip attribute)](bpy.types.SceneStrip.html#bpy.types.SceneStrip.use_flip_y)   - [(bpy.types.ShaderFxFlip attribute)](bpy.types.ShaderFxFlip.html#bpy.types.ShaderFxFlip.use_flip_y) - [use_float (bpy.types.EffectStrip attribute)](bpy.types.EffectStrip.html#bpy.types.EffectStrip.use_float)   - [(bpy.types.ImageStrip attribute)](bpy.types.ImageStrip.html#bpy.types.ImageStrip.use_float)   - [(bpy.types.MaskStrip attribute)](bpy.types.MaskStrip.html#bpy.types.MaskStrip.use_float)   - [(bpy.types.MetaStrip attribute)](bpy.types.MetaStrip.html#bpy.types.MetaStrip.use_float)   - [(bpy.types.MovieClipStrip attribute)](bpy.types.MovieClipStrip.html#bpy.types.MovieClipStrip.use_float)   - [(bpy.types.MovieStrip attribute)](bpy.types.MovieStrip.html#bpy.types.MovieStrip.use_float)   - [(bpy.types.SceneStrip attribute)](bpy.types.SceneStrip.html#bpy.types.SceneStrip.use_float) - [use_flow_pressure (bpy.types.Brush attribute)](bpy.types.Brush.html#bpy.types.Brush.use_flow_pressure) - [use_foam (bpy.types.OceanModifier attribute)](bpy.types.OceanModifier.html#bpy.types.OceanModifier.use_foam) - [use_foam_particles (bpy.types.FluidDomainSettings attribute)](bpy.types.FluidDomainSettings.html#bpy.types.FluidDomainSettings.use_foam_particles) - [use_follow (bpy.types.Screen attribute)](bpy.types.Screen.html#bpy.types.Screen.use_follow) - [use_fractions (bpy.types.FluidDomainSettings attribute)](bpy.types.FluidDomainSettings.html#bpy.types.FluidDomainSettings.use_fractions) - [use_frame_end (bpy.types.FModifierStepped attribute)](bpy.types.FModifierStepped.html#bpy.types.FModifierStepped.use_frame_end) - [use_frame_interpolate (bpy.types.SpeedControlStrip attribute)](bpy.types.SpeedControlStrip.html#bpy.types.SpeedControlStrip.use_frame_interpolate) - [use_frame_range (bpy.types.Action attribute)](bpy.types.Action.html#bpy.types.Action.use_frame_range) - [use_frame_start (bpy.types.FModifierStepped attribute)](bpy.types.FModifierStepped.html#bpy.types.FModifierStepped.use_frame_start) - [use_freestyle (bpy.types.RenderSettings attribute)](bpy.types.RenderSettings.html#bpy.types.RenderSettings.use_freestyle)   - [(bpy.types.ViewLayer attribute)](bpy.types.ViewLayer.html#bpy.types.ViewLayer.use_freestyle) - [use_fresnel_edit (bpy.types.PreferencesView attribute)](bpy.types.PreferencesView.html#bpy.types.PreferencesView.use_fresnel_edit) - [use_frontface (bpy.types.Brush attribute)](bpy.types.Brush.html#bpy.types.Brush.use_frontface) - [use_frontface_falloff (bpy.types.Brush attribute)](bpy.types.Brush.html#bpy.types.Brush.use_frontface_falloff) - [use_full_resolution (bpy.types.Scopes attribute)](bpy.types.Scopes.html#bpy.types.Scopes.use_full_resolution) - [use_fuzzy_all (bpy.types.GreasePencilLineartModifier attribute)](bpy.types.GreasePencilLineartModifier.html#bpy.types.GreasePencilLineartModifier.use_fuzzy_all) - [use_fuzzy_intersections (bpy.types.GreasePencilLineartModifier attribute)](bpy.types.GreasePencilLineartModifier.html#bpy.types.GreasePencilLineartModifier.use_fuzzy_intersections) - [use_generated_float (bpy.types.Image attribute)](bpy.types.Image.html#bpy.types.Image.use_generated_float)   - [(bpy.types.UDIMTile attribute)](bpy.types.UDIMTile.html#bpy.types.UDIMTile.use_generated_float) - [use_geometry_nodes_lists (bpy.types.PreferencesExperimental attribute)](bpy.types.PreferencesExperimental.html#bpy.types.PreferencesExperimental.use_geometry_nodes_lists) - [use_geometry_space_chain (bpy.types.GreasePencilLineartModifier attribute)](bpy.types.GreasePencilLineartModifier.html#bpy.types.GreasePencilLineartModifier.use_geometry_space_chain) - [use_ghost_custom_colors (bpy.types.GreasePencil attribute)](bpy.types.GreasePencil.html#bpy.types.GreasePencil.use_ghost_custom_colors) - [use_glob (bpy.types.PathCompare attribute)](bpy.types.PathCompare.html#bpy.types.PathCompare.use_glob) - [use_global_coords (bpy.types.FieldSettings attribute)](bpy.types.FieldSettings.html#bpy.types.FieldSettings.use_global_coords) - [use_global_instance (bpy.types.ParticleSettings attribute)](bpy.types.ParticleSettings.html#bpy.types.ParticleSettings.use_global_instance) - [use_global_undo (bpy.types.PreferencesEdit attribute)](bpy.types.PreferencesEdit.html#bpy.types.PreferencesEdit.use_global_undo) - [use_glow_under (bpy.types.ShaderFxGlow attribute)](bpy.types.ShaderFxGlow.html#bpy.types.ShaderFxGlow.use_glow_under) - [use_goal (bpy.types.SoftBodySettings attribute)](bpy.types.SoftBodySettings.html#bpy.types.SoftBodySettings.use_goal) - [use_gpencil_automerge_strokes (bpy.types.ToolSettings attribute)](bpy.types.ToolSettings.html#bpy.types.ToolSettings.use_gpencil_automerge_strokes) - [use_gpencil_canvas_xray (bpy.types.View3DOverlay attribute)](bpy.types.View3DOverlay.html#bpy.types.View3DOverlay.use_gpencil_canvas_xray) - [use_gpencil_draw_additive (bpy.types.ToolSettings attribute)](bpy.types.ToolSettings.html#bpy.types.ToolSettings.use_gpencil_draw_additive) - [use_gpencil_draw_onback (bpy.types.ToolSettings attribute)](bpy.types.ToolSettings.html#bpy.types.ToolSettings.use_gpencil_draw_onback) - [use_gpencil_edit_lines (bpy.types.View3DOverlay attribute)](bpy.types.View3DOverlay.html#bpy.types.View3DOverlay.use_gpencil_edit_lines) - [use_gpencil_fade_gp_objects (bpy.types.View3DOverlay attribute)](bpy.types.View3DOverlay.html#bpy.types.View3DOverlay.use_gpencil_fade_gp_objects) - [use_gpencil_fade_layers (bpy.types.View3DOverlay attribute)](bpy.types.View3DOverlay.html#bpy.types.View3DOverlay.use_gpencil_fade_layers) - [use_gpencil_fade_objects (bpy.types.View3DOverlay attribute)](bpy.types.View3DOverlay.html#bpy.types.View3DOverlay.use_gpencil_fade_objects) - [use_gpencil_grid (bpy.types.View3DOverlay attribute)](bpy.types.View3DOverlay.html#bpy.types.View3DOverlay.use_gpencil_grid) - [use_gpencil_multiedit_line_only (bpy.types.View3DOverlay attribute)](bpy.types.View3DOverlay.html#bpy.types.View3DOverlay.use_gpencil_multiedit_line_only) - [use_gpencil_onion_skin (bpy.types.View3DOverlay attribute)](bpy.types.View3DOverlay.html#bpy.types.View3DOverlay.use_gpencil_onion_skin) - [use_gpencil_onion_skin_active_object (bpy.types.View3DOverlay attribute)](bpy.types.View3DOverlay.html#bpy.types.View3DOverlay.use_gpencil_onion_skin_active_object) - [use_gpencil_project_only_selected (bpy.types.ToolSettings attribute)](bpy.types.ToolSettings.html#bpy.types.ToolSettings.use_gpencil_project_only_selected) - [use_gpencil_select_mask_point (bpy.types.ToolSettings attribute)](bpy.types.ToolSettings.html#bpy.types.ToolSettings.use_gpencil_select_mask_point) - [use_gpencil_select_mask_segment (bpy.types.ToolSettings attribute)](bpy.types.ToolSettings.html#bpy.types.ToolSettings.use_gpencil_select_mask_segment) - [use_gpencil_select_mask_stroke (bpy.types.ToolSettings attribute)](bpy.types.ToolSettings.html#bpy.types.ToolSettings.use_gpencil_select_mask_stroke) - [use_gpencil_show_directions (bpy.types.View3DOverlay attribute)](bpy.types.View3DOverlay.html#bpy.types.View3DOverlay.use_gpencil_show_directions) - [use_gpencil_show_material_name (bpy.types.View3DOverlay attribute)](bpy.types.View3DOverlay.html#bpy.types.View3DOverlay.use_gpencil_show_material_name) - [use_gpencil_thumbnail_list (bpy.types.ToolSettings attribute)](bpy.types.ToolSettings.html#bpy.types.ToolSettings.use_gpencil_thumbnail_list) - [use_gpencil_vertex_select_mask_point (bpy.types.ToolSettings attribute)](bpy.types.ToolSettings.html#bpy.types.ToolSettings.use_gpencil_vertex_select_mask_point) - [use_gpencil_vertex_select_mask_segment (bpy.types.ToolSettings attribute)](bpy.types.ToolSettings.html#bpy.types.ToolSettings.use_gpencil_vertex_select_mask_segment) - [use_gpencil_vertex_select_mask_stroke (bpy.types.ToolSettings attribute)](bpy.types.ToolSettings.html#bpy.types.ToolSetting