---
title: Modifiers
order: 7
---

Modifiers compose primitives into complete shapes. Boolean, mirror, array, twist — every one of them runs on the SDF directly, so the result is always a single, watertight surface. No mesh repair, no double-sided faces, no booleans that fall apart at zoom.

## Where modifiers live

The Chisel modifier list lives in the *Modifier* tab of the Properties editor — it replaces Blender's stock modifier panel while the Chisel engine is active. A big **Add Modifier** button opens the full menu; the toolbar above the list has *Collapse All*, *Expand All*, and an options menu (the three-dot button) with an *Expand* toggle and *Delete All*. The pie menu (`Q`) also exposes the most common operations: boolean Difference / Union / Intersect, mirror, and quick adjustments.

Each modifier collapses into a header showing its name and active state. Click the header to expand its options. New modifiers stay collapsed unless you turn on *Expand* in the toolbar options menu.

## Add Modifier and Swap Modifier

The **Add Modifier** menu groups every modifier: Boolean (Difference / Union / Intersect), Solidify, Mirror, Array, Emboss, Engrave, Twist, Bend. Booleans and Emboss / Engrave act on the selection — select the operand shapes, make the host active, then pick the entry.

**Swap Modifier** rewrites the operation of every modifier that targets the selected shapes in one step — switch a stack of Difference cuts to Union, or flip a boolean into Emboss, without touching the targets one by one. It is on the `RMB` context menu (Chisel tool active) and as the *Shift+click* action of the pie menu's modifier buttons. The operation cycle hotkeys `;` and `'` step the same swap through Difference → Union → Intersect → Emboss → Engrave (Slice excluded).

## Pinned modifiers

![a pinned Chisel modifier held at the bottom of the stack](../assets/modifiersettings-pined.webp)

Each modifier row header has a **pin** toggle (operator tooltip: *Pin or unpin a Chisel modifier (pinned modifiers stay at the end of the stack)*). A pinned modifier is held at the **end** (bottom) of the stack, and every newly added modifier inserts *above* the pins. Unpinning drops the modifier back to the bottom of the non-pinned region. The Move Up / Move Down arrows will not carry a modifier across the pin boundary, so pinned modifiers stay grouped at the bottom.

Pin a Solidify or a final Mirror, for example, and any boolean you add afterward slots in ahead of it — so the shell or the symmetry always applies last.

## Categories

- **[Boolean](boolean.md)** — Difference, Union, Intersect, Slice. With smooth blending.
- **[Mirror](mirror.md)** — Reflect across one or more axes with optional smooth seam.
- **[Array](array.md)** — Linear and circular repetition.
- **[Solidify](solidify.md)** — Hollow into a shell of given thickness.
- **[Emboss & Engrave](emboss-engrave.md)** — Push a target shape outward (Emboss) or inward (Engrave).
- **[Twist & Bend](twist-bend.md)** — Deform along an axis.

## Apply

**Apply** (the checkmark button in the Chisel object panel, after *To Mesh* / *Clean* / *Rebuild Mesh*) converts the whole chain to a static triangulated mesh and removes the source SDF shapes in one click. A *Delete Sources* option (on by default, in the redo panel) keeps the source shapes alongside the new mesh when turned off. See [Apply Modifiers](../operations/apply-modifiers.md).

## Modifier UI tips

- **Header buttons** — each row header has Move Up, Move Down, a **pin** toggle, and Remove, in that order.
- **Quick boolean hotkeys** (`Alt + −/=/\\` or `NumPad −/+//`) bypass the panel entirely: select operands, make destination active, tap the key.
- **`Ctrl + D`** duplicates a shape together with its modifier graph — children, boolean and displace targets, and curve sources come along, and any external boolean that referenced the original picks up the copy too (group cuts stay group cuts).
- **Adjust modal** — `B` opens *Adjust Rounding* on a primitive; `Ctrl+B` opens it on the active boolean modifier. While active, keys `1–5` switch profiles instantly: `1` Round, `2` Sharp, `3` Soft, `4` Tight, `5` Chamfer; `S` toggles between the radius and the Chamfer Smooth value.