Editor Hotkeys

Mouse

 * Holding Right Mouse Button – Camera mode
 * + Move – Pitch/orbit
 * + Left Mouse Button + Move – Move


 * Mouse Wheel – Zoom
 * Shift + Mouse Wheel – Scale brush or prop

Camera and Control

 * WASD – Move camera
 * Arrow Keys – Pitch/orbit camera
 * q/e – Move camera vertically
 * r/f – Zoom camera
 * Home – Center to player
 * c – Cycle camera presets (top down, front, side, free)

Menu and Tool Functions

 * Esc – Back/cancel
 * Ctrl + s – Save
 * F1 – Help
 * F2 – Biome mode (successive presses cycle through tools)
 * F3 – Paint mode
 * F4 – Sculpt mode (successive presses cycle through tools)
 * F5 – Prop mode (successive presses cycle through tools)
 * Return/Enter – Tool menu
 *  ' and Shift + '  – Cycle between tool modes

Editing

 * Shift + Mouse Wheel – Resize brush/prop
 * Spacebar – Biome, material or prop gallery
 * Holding Alt – Invert tool or snap current prop to another prop
 * Ctrl + c – Copy current prop (only works for some props)
 * Ctrl + m – Swap current prop mesh
 * Delete – Delete current prop
 * Shift + b – Brain on selected prop
 * Shift + p – Prop edit menu on selected prop
 * Shift + d – Character studio on selected prop
 * Holding ctrl – Grid snap
 * g – Toggle grid snap
 * Ctrl + g – Toggle workplane
 * Ctrl + z – Undo
 * Ctrl + y – Redo

Brain

 * Esc – Back/cancel
 * Ctrl + c – Copy tile/line
 * Ctrl + v – Paster tile/line
 * Arrow Keys – Select tile
 * Return/Enter – Swap/select tile

Gallery

 * Home/End – First/last page
 * Page Up/Down – Previous/next page

Xbox Controller

 * Left thumbstick moves the cursor horizontally.
 * Using X brings your cursor down in the world, while using Y brings your cursor up in the world.
 * Right thumbstick pans the camera.
 * Pressing in on the Right thumbstick will cycle through different zooming distances.
 * Right Bumper + Up/Down on the Left Joystick zooms the camera in/out.
 * Right Bumper + A centers the camera on the player.
 * Right Bumper + B cycles through the camera presets (top down, front, side, free).
 * A button activates and selects buttons on the tools menu.
 * Right Trigger places props in prop mode.
 * Left Trigger snaps an object to the ground in prop mode.
 * When sculpting, Right Trigger is for positive sculpting like expanding and adding terrain. Left Trigger switches to negative sculpting such as eroding and subtracting terrain.
 * Holding Left Bumper brings up menu wheel and scale option (for props it gives additional menu options: Y = Brain, X = Delete, B = Character Studio, A = Edit).
 * Left and Right on the D-Pad cycles through paint and biome palettes.
 * Holding down on the D-Pad turns on and off snap to grid.
 * Pressing up on the D-Pad opens up your gallery (Materials, Biome or Prop gallery).
 * Pressing the View button will use the undo tool.
 * View + Right thumbstick to the left cycles through undo points.
 * View + Right thumbstick to the right cycles through redo points.

Source: Project Spark Instruction Manual (Handy Keyboard Maps and Handy Controller Maps).