Chisel
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Boolean

A Boolean joins one shape, the cutter, to another, the host. The cutter is the Boolean’s target. The result stays live: move, scale or round either shape and the join follows.

The sphere clicked, the box Shift-clicked, Alt + -: the sphere cuts a bowl out of the box

Operations

Difference

Cuts the cutter’s volume out of the host. Key: Alt + - or NumPad -. The cutter’s outline is red.

Union

Merges the cutter and the host into one solid. Key: Alt + = or NumPad +. The cutter’s outline is green.

Alt + =, then Ctrl + B and a drag: the sphere joins the box and the seam is filleted

Intersect

Keeps only the volume the cutter and the host share. Key: Alt + \ or NumPad /. The cutter’s outline is blue.

Alt + backslash: only the overlap of the box and the sphere is left

Slice

Splits the host in two along the cutter. Chisel copies the host and names the copy _slice. The host gets a Difference with the cutter, and the copy gets an Intersect with the same cutter, so one shape is the host with a hole and the other is the piece that was cut out. Both use the same cutter, so moving it moves the cut on both.

Slice has no key, and the panel’s Operation list has no Slice entry: the panel shows the two Booleans it made. The cutter’s outline is red.

Pie Slice, then the box hidden with H: the cut-out piece is a shape of its own

Join keys and buttons

The keys above and the join buttons of the pie (South) and the right-click Modifiers menu join every selected Chisel shape into the active one, the host. Each selected shape becomes the cutter of a new Boolean at the end of the host’s stack (before any pinned modifier), and:

  • stops rendering on its own and shows its outline instead, faint until selected;
  • becomes a child of the host, if it had no parent;
  • stays selected, the first one active.

The keys need the Chisel tool, a Chisel shape active and another one selected. Add Modifier in the panel adds an empty Boolean: its Target is picked in the panel.

Duplicate as Boolean

Alt + D copies the active shape, with the shapes its own joins use, and joins the copy into the original’s stack: a new Boolean at the end of the stack (before any pinned modifier), Union with a Blend of 0.5. The copy becomes that Boolean’s cutter and a child of the original, and moves with the mouse until you click. Change its operation or blend like any other Boolean’s.

Alt + D on a rounded box, a move and a click: the copy joins the box with a wide blend

It needs the Chisel tool and a Chisel shape active. On anything else, Alt + D stays Blender’s Duplicate Linked.

Changing the operation

Select the cutter, then:

  • press ' for the next operation or ; for the previous one. The order is Difference, Union, Intersect, Emboss, Engrave, Carve, then back to Difference;
  • or click another join button in the pie or the right-click Modifiers menu. When only that one cutter is selected, its current operation is highlighted, and a click changes it instead of adding a new Boolean. Shift + click adds a new one;
  • or click the symbol in front of the cutter’s name in the Tape tree and pick a join from the list.

The keys and buttons change every modifier that uses the selected cutter, on every host. Slice is not in the ' / ; order. Changing a sliced cutter to another operation deletes the _slice copy. The panel’s Operation list changes only that one Boolean.

' pressed six times: Union, Intersect, Emboss, Engrave, Carve, back to Difference

Settings

The Boolean in the Chisel Modifiers panel, Blend on, Chamfer profile

SettingDefaultRangeWhat it does
Expand arrowclosedShows or hides the settings.
HeaderThe operation and the cutter, e.g. Difference: Sphere; (no target) in red when the cutter was deleted.
Move up, Move downMove the Boolean in the stack.
PinoffKeep the Boolean at the end of the stack.
Remove (X)Delete the Boolean.
Targetnoneany Chisel shape but the hostThe cutter. A cutter picked here stops rendering too, but is not made a child of the host.
OperationDifferenceDifference, Union, IntersectWhat the cutter does.
BlendoffFillets the seam. It is ticked automatically when you drag the blend radius above 0 with Ctrl + B, the Blend arc or the pie.
ProfileRoundRound, Sharp, Soft, Tight, ChamferThe fillet’s profile. Shown with Blend on.
Outer0 m0 and up (soft max 2)The fillet radius. Shown with Blend on.
Smooth0 m0 and up (soft max 0.5)Rounds the two edges of a Chamfer fillet. Shown on Chamfer.
Material Blend1.000 and up (soft max 3)Width of the colour change across the seam, as a multiple of the fillet: 0 is a crisp colour line, above 1 the colours bleed wider. Works with Blend off too.

Viewport handles

HandleLooks likeDrag or clickKeys while dragging
Blend arca blue arc, bottom right of a selected cutterDrag outward: a wider blend on every modifier that uses the selectionShift precision, Ctrl snap, 1–5 profile, S Smooth
Cutter outlinethe cutter’s silhouette in its join’s colourDisplay only: click the shape there to select itnone
Target dota dot at the cutter’s origin. Off by defaultClick: select the cutter, and show it if hiddennone

Keys

KeyWhat it does
Alt + -, Alt + =, Alt + \Difference, Union, Intersect
' / ;Next / previous operation
Ctrl + BDrag the blend of every modifier that uses the selected shapes: away from the active shape is wider. Keys: see Blending

Ctrl + B on the cutter, a drag, 5 for Chamfer, 1 for Round, a click

In the menus

  • Pie Q, South: Boolean Difference, Boolean Union, Boolean Intersect, Slice, then Emboss, Engrave, Carve.
  • Pie, East, with the host active: per Boolean, the profile icons, the blend radius (a drag), the Chamfer’s Smooth and the cutter’s name.
  • Pie, South-West, with a cutter selected: the five blend profile icons, Blend (a drag) and, on Chamfer, Smooth.
  • Right-click, with a cutter selected: Blend Profiles ▸, Blend and, on Chamfer, Smooth.
  • Right-click ▸ Modifiers: the same seven join buttons as the pie.
  • Tape tree: right-click a cutter for its Blend, profile, radius, Smooth and Material Blend.

Tips

Select the cutter, not the host

', ;, Ctrl + B and the Blend arc act on the modifiers that use the selected shapes.

Limits and known issues

A removed Boolean leaves its cutter hidden

Removing a Boolean, or picking another Target, does not show the old cutter again. It is listed under Unused in the Tape tree; tick its Render box in Object Properties ▸ SDF.

See also