Brings up the last tool used

`Ctrl` + `R`

All hotkeys for Modo (Windows)

General/System Help	`F1`
General/System New scene	`Ctrl` + `N`
General/System Open saved scene	`Ctrl` + `O`
General/System Open saved image	`Ctrl` + `I`
General/System Close current scene	`Ctrl` + `W`
General/System Close all open scenes	`Ctrl` + `Shift` + `W`
General/System Save current scene	`Ctrl` + `S`
General/System Save scene as	`Ctrl` + `Shift` + `S`
General/System Quit Modo	`Ctrl` + `Q`
General/System Config file save	`Alt` + `F12`
General/System Run script	`Shift` + `F5`
General/System Undo	`Ctrl` + `Z`
General/System Redo	`Ctrl` + `Shift` + `Z`
General/System Cut	`Ctrl` + `X`
General/System Copy	`Ctrl` + `C`
General/System Paste	`Ctrl` + `V`
General/System Delete (not available in Items mode)	`Delete`
General/System Brings up the last tool used	`Ctrl` + `R`
General/System Brings up the last tool used, ignoring UI interactions and selections	`Alt` + `R`
General/System Layout switcher, organized by most recent	`Ctrl` + `Tab`
Navigation (Viewports) Rotate view	`Alt` + `Click`
Navigation (Viewports) Rotate viewport Z axis (bank) view	`Alt` + `Middle-click`
Navigation (Viewports) Flick' rotate	`Alt` + `Right-click`
Navigation (Viewports) Pan view	`Shift` + `Alt` + `Left-click`
Navigation (Viewports) Pan up/down only	`Shift` + `Alt` + `Right-click`
Navigation (Viewports) Zoom to mouse position	`Ctrl` + `Alt` + `Left-click`
Navigation (Viewports) Box zoom	`Ctrl` + `Alt` + `Right-click`
Navigation (Viewports) Zoom in (only in component modes)	`. (period)`
Navigation (Viewports) Zoom in x2	`Shift` + `. (period)`
Navigation (Viewports) Zoom out (only in component modes)	`, (comma)`
Navigation (Viewports) Zoom out x2	`Shift` + `, (comma)`
Navigation (Viewports) Center the view on the cursor's position	`G`
Navigation (Viewports) Turntable (only in component modes)	`/`
Navigation (Viewports) When turntable is running, displays upright turntable	`Shift` + `/`
Navigation (Viewports) Zoom view in and out to mouse pointer	`Mouse Wheel Scroll`
Navigation (Viewports) Fit (zoom to scene extents/all items)	`A`
Navigation (Viewports) Fit selected (zooms to selected elements)	`Shift` + `A`
Navigation (Viewports) Align selected (aligns view to the current selection)	`Ctrl` + `A`
Navigation (Viewports) Fit and align selected (zooms and aligns the view to the current selection)	`Ctrl` + `Shift` + `A`
3D Viewport Options Open the viewport options pop-over	`O`
3D Viewport Options Maximize/minimize the viewport within the group	`0`
3D Viewport Options Perspective	`. (decimal)`
3D Viewport Options Top (press again to toggle top/bottom view)	`1`
3D Viewport Options Bottom	`Shift` + `1`
3D Viewport Options Front (press again to toggle front/back view)	`2`
3D Viewport Options Back	`Shift` + `2`
3D Viewport Options Right (press again to toggle right /left view)	`3`
3D Viewport Options Left	`Shift` + `3`
3D Viewport Options Shaded	`Shift` + `4`
3D Viewport Options Texture	`Shift` + `5`
3D Viewport Options Reflection	`Shift` + `6`
3D Viewport Options Wireframe	`Shift` + `7`
3D Viewport Options Solid	`Shift` + `8`
3D Viewport Options Vertex Map	`Shift` + `9`
3D Viewport Options Wireframe None	`/`
3D Viewport Options Wireframe Light	`Shift` + `/`
3D Viewport Options Wireframe Dark	`Ctrl` + `/`
Item List In Items selection mode, locate selected item (layer). In other modes flip polygons	`F`
Item List Expand/close all (also in Shader Tree)	`Shift` + `click`
Item List Swap foreground/background layers	`' (apostrophe)`
Item List Duplicate selected layer(s) (only in Items mode)	`Ctrl` + `D`
Item List Instance selected layer(s) (only in Items mode)	`Shift` + `D`
Item List New Mesh Item	`N`
Item List New locator item (only in Items mode)	`L`
Channel list Select modifier input	`I`
Channel list Select modifier output	`O`
Channel list Channel haul on (only in Items mode)	`C`
Floating Windows Modeling toolbox	`F2`
Floating Windows Sculpt/paint toolbox	`F3`
Floating Windows Setup toolbox	`F4`
Floating Windows Command History viewport	`F5`
Floating Windows Presets viewport	`F6`
Floating Windows Graph Editor	`F7`
Floating Windows Render preview	`F8`
Floating Windows Snapping pop-over	`F11`
Floating Windows Toggle window visibility	` (backtick)
Pie Menus Layout switch favorites	`Ctrl` + ` (backtick)
Pie Menus GL viewport toggles	`Ctrl` + `1`
Pie Menus GL viewport style	`Ctrl` + `2`
Pie Menus GL viewport view type	`Ctrl` + `Space`
Pie Menus Open pop-over	`Ctrl` + `3`
Pie Menus Selection mode/Transform tools	`Alt` + `Q`
Pie Menus Open palette	`Alt` + ` (backtick)
Pie Menus Properties and options	`Shift` + ` (backtick)
Pie Menus Brushes pie menu (only when a Brush tool is active)	`B`
Pie Menus Animation shortcuts (only in the Animation layout)	`Alt` + `Space`
General Modeling Drops active tool	`Q`
General Modeling "Tool properties pop-over	`K`
General Modeling Escape current operation/drop active selection	`Esc`
General Modeling Cycle-through Component modes	`Space`
General Modeling Toggle Component mode to Item Mode (or last mode)	`Shift` + `Space`
General Modeling Tool handle smaller	`-`
General Modeling Toggle tool handle visibility (not on the numeric keypad; only on Mac)	`0`
General Modeling Reset tool attributes	`Ctrl` + `D`
General Modeling Select layer 1-10	`Shift` + `0-9`
General Modeling Quick access pop-over	`Alt` + `Space`
General Modeling Assign material tag	`M`
General Modeling Toggle subdivision surfaces	`Tab`
General Modeling Toggle Catmull-Clark subdivision surfaces	`Shift` + `Tab`
General Modeling Increase/decrease subdivision level	`Keypad +/-`
Action Center/Axis Origin	`Alt` + `W`
Action Center/Axis Pivot	`Alt` + `E`
Action Center/Axis Automatic	`Alt` + `A`
Action Center/Axis Selection	`Alt` + `S`
Action Center/Axis Selection center, auto axis	`Alt` + `D`
Action Center/Axis Displays pie menu	`Alt` + `Q`
Action Center/Axis Screen	`Alt` + `F`
Action Center/Axis Element	`Alt` + `Z`
Action Center/Axis Local	`Alt` + `X`
Action Center/Axis Pivot center, parent axis	`Alt` + `G`
Selection (Modelling) Select all	`Alt` + `Shift` + `A`
Selection (Modelling) More (select next plausible element in loop)	`Arrow Up`
Selection (Modelling) Select expand	`Shift` + `Arrow Up`
Selection (Modelling) Less (de-select last element)	`Arrow Down`
Selection (Modelling) Shrink	`Shift` + `Arrow Down`
Selection (Modelling) Select previous loop	`Arrow Left`
Selection (Modelling) Select previous loop add	`Shift` + `Arrow Left`
Selection (Modelling) Select next loop	`Arrow Right`
Selection (Modelling) Select next loop add	`Shift` + `Arrow Right`
Selection (Modelling) Select loop	`L`
Selection (Modelling) Select ring	`Alt` + `L`
Selection (Modelling) Connected	`]`
Selection (Modelling) Invert selection	`[`
Selection (Modelling) Close loop	`Shift` + `]`
Selection (Modelling) Select between	`Shift` + `G`
Selection (Modelling) Convert selection to vertices	`Alt` + `1`
Selection (Modelling) Convert selection to edges	`Alt` + `2`
Selection (Modelling) Convert selection to polygons	`Alt` + `3`
Selection (Modelling) Select through toggle	`; (semicolon)`
Hide/Lock Geometry Hide selected	`H`
Hide/Lock Geometry Hide unselected	`Shift` + `H`
Hide/Lock Geometry Hide invert (toggle state)	`Ctrl` + `H`
Hide/Lock Geometry Show	`U`
Hide/Lock Geometry Lock selected	`J`
Hide/Lock Geometry Lock unselected	`Shift` + `J`
Hide/Lock Geometry Lock invert (toggle state)	`Ctrl` + `J`
Hide/Lock Geometry Unlock	`I`
Work Plane Align to geometry under cursor	`Home`
Work Plane Align to selection (average of all selected)	`Shift` + `Home`
Work Plane Align to viewport	`Ctrl` + `Home`
Work Plane Reset the Work Plane	`End`
Work Plane Open Work Plane pop-over	`Shift` + `End`
Work Plane Walk +	`Page Up`
Work Plane Walk -	`Page Down`
Work Plane Toggle visibility	`Keypad * (asterisk)`
Work Plane Offset Work Plane to geometry position under cursor	`Alt` + `O`
Snapping Toggle snap state (hold with tool active for temporary snap)	`X`
Snapping Open snapping pop-over	`F11`
Snapping Element snap	`Ctrl` + `Shift` + `T`
Tools Move	`W`
Tools Rotate	`E`
Tools Planar rotate	`Alt` + `Shift` + `E`
Tools Scale	`R`
Tools Uniform scale	`Shift` + `R`
Tools Transform	`Y`
Tools Bend	`Ctrl` + `E`
Tools Element move (Tweak)	`T`
Tools Soft drag	`Ctrl` + `T`
Tools Flex tool	`Shift` + `Y`
Tools Smooth tool	`Shift` + `S`
Tools Extrude	`Shift` + `X`
Tools Radial sweep	`Shift` + `L`
Tools Grow quad row from edge	`Shift` + `Q`
Tools Extend edge	`Z`
Tools Mirror tool	`Shift` + `V`
Tools Remove	`Backspace`
Tools Collapse	`Ctrl` + `Backspace`
Tools Bevel	`B`
Tools Polygon bevel	`Shift` + `B`
Tools Sketch extrude	`Alt` + `B`
Tools Create polygon of given type from vertex selection	`Ctrl` + `B`
Tools Edge slice	`C`
Tools Polygon slice	`Shift` + `C`
Tools Loop slice	`Alt` + `C`
Tools Subdivide selected geometry	`D`
Tools Open subdivide options	`Shift` + `D`
Tools Flip polygon normal	`F`
Tools Split face by selected vertices	`Ctrl` + `L`
Tools Make polygon	`P`
Tools Triple polygons (convert to triangles)	`Shift` + `T`
Tools Spin edge	`V`
Tools Spin quads curves	`Alt` + `V`
Tools Make open curve	`Shift` + `O`
Tools Make closed curve	`Ctrl` + `P`
Tools Weight tool	`Shift` + `W`
Tools Morph tool	`Shift` + `M`
Paint And Sculpt Open brush tips pie menu (only when tool is active)	`B`
Paint And Sculpt Open large color picker pop-over (hover over UI color picker)	`O`
Paint And Sculpt Swap foreground/background colors	`S`
Paint And Sculpt Image ink rotate left/right	`E` / `R`
Paint And Sculpt Image ink scale up/down	`D` / `F`
Paint And Sculpt Adjust offset amount (sticky key, only while Brush tool is active)	`Shift` + `Z`
Paint And Sculpt Subdivision level up	`Alt` + `(numeric pad) +`
Paint And Sculpt Subdivision level down	`Alt` + `(numeric pad) -`
Paint And Sculpt Current level up	`Ctrl` + `(numeric pad) +`
Paint And Sculpt Current level down	`Ctrl` + `(numeric pad) -`
Camera Move camera item	`Shift` + `Alt` + `Click` + `Drag`
Camera Move up/down direction only	`Shift` + `Alt` + `right-click` + `Drag`
Camera Rotate around target distance	`Alt` + `Click` + `Drag`
Camera Rotate around Z axis	`Alt` + `Right-click` + `Drag`
Camera Image ink scale up/down	`Ctrl` + `Middle-click` + `Drag`
Camera Move forward/backward only	`Ctrl` + `Alt` + `Click+drag`
Camera Adjust focal length	`Ctrl` + `Alt` + `Right-click+Drag`
Camera Zooms to cursor	`Roll Mouse Wheel`
Camera Auto focus camera (only in a viewport defined as Camera and with auto-focus enabled)	`Ctrl` + `A`
Camera Restart preview (only in the Preview viewport)	`Ctrl` + `F`
Animation Select all animated items	`Shift` + `Z`
Animation Select all animated channels	`Z`
Animation Group selected items (under group locator)	`Ctrl` + `G`
Animation Parent in place	`P`
Animation Parent	`Ctrl` + `P`
Animation Unparent in place	`Shift` + `P`
Animation Unparent	`Ctrl` + `Shift` + `P`
Animation Go to first frame	`Shift` + `Arrow Up`
Animation Go to first keyframe	`Ctrl` + `Arrow Up`
Animation Go to previous keyframe	`Ctrl` + `Arrow Left`
Animation Go back one frame	`Shift` + `Arrow Left`
Animation Start/stop animation playback	`/`
Animation Go forward one frame	`Shift` + `Arrow Right`
Animation Go to next keyframe	`Ctrl` + `Arrow Right`
Animation Go to last keyframe	`Ctrl` + `Arrow Down`
Animation Key transforms	`Shift` + `Y`
Animation Key rotations	`Shift` + `E`
Animation Key positions	`Shift` + `W`
Animation Key scale	`Shift` + `R`
Animation Key selected channels	`S`
Animation Key selected items	`Shift` + `S`
Animation Fit selected	`A`
Animation Fit visible	`Ctrl` + `F`
Animation Fit visible width	`Shift` + `F`
Animation Pan view	`Alt` +click
Animation Scale view	`Ctrl` + `Alt` + `Click`
Animation Scale graph size	`Alt` + `Right-click`
Animation Box zoom (drag box to zoom)	`Ctrl` + `Alt` + `Right-click`
Animation Paste insert keyframes to selected channels	`Ctrl` + `Shift` + `V`
Animation Paste replace keyframes to selected channels	`Ctrl` + `Alt` + `V`
Render Render	`F9`
Render Render visible	`Ctrl` + `F9`
Render Render selected	`Shift` + `F9`
Render Render current view	`F10`
Render Open render display window	`Alt` + `Shift` + `F9`
Render Focus under cursor	`Ctrl` + `F`
Render Preview zoom	mouse wheel
Render Jump the preview out to the original focal length (only when zoomed in)	middle-click+drag