---
title: Rounding
order: 2
---

Rounding softens the edges of a *single primitive*. Every primitive that has hard edges exposes a rounding control in the *Object Properties* panel.

![Rounding](../assets/gizmo-rounding.webp)

## Parameters

- **Rounding**: edge radius (`0.0–10.0`, soft max `2.0`, default `0.0`)
- **Profile**: Round / Sharp / Soft / Tight / Chamfer (see [Profiles](profiles.md))
- **Chamfer Smooth** *(when Profile = Chamfer)*: softens where the chamfer meets the faces (`0.0–5.0`, soft max `0.5`)

## Which primitives support rounding

| Primitive | Rounding | Bevel |
|---|:---:|:---:|
| Box | ✓ | — |
| Cylinder | ✓ | — |
| Cone | ✓ | — |
| Prism | ✓ | ✓ |
| Trapezoid | ✓ | ✓ |
| Curve | ✓ | — |
| Sphere |: *(already smooth)* | — |
| Capsule |: *(already smooth)* | — |
| Torus |: *(already smooth)* | — |
| Curve Tube |: *(swept smooth)* | — |
| Curve Revolve | ✓ | — |
| Ngon | per corner | per corner |

## Bevel for Prism and Trapezoid

Prism and Trapezoid have an extra **Bevel** control independent of *Rounding*. *Rounding* applies to the top and bottom rims; *Bevel* applies to the vertical (or slanted) corner edges. Both have their own profile selector and chamfer-smooth control, so you can pair, say, *Round* on the rims with *Sharp* on the corners.

## Workflow

1. Select the primitive.
2. Open *Object Properties → SDF*.
3. Drag the **Rounding** slider, or press `B` over the primitive for a live drag modal.
4. Pick the profile (Round / Sharp / Soft / Tight / Chamfer): the dropdown or `1`–`5` in the modal.
5. If you picked Chamfer, push **Chamfer Smooth** up to soften the bevel-meets-face seam.

## Adjust modal (`B`)

Press `B` over a primitive to drag its rounding radius live. You can also click the rounding gizmo dot in the viewport to enter the same modal, see [Interface: Gizmos](../interface/gizmos.md).

| Action | Effect |
|---|---|
| **LMB-drag** | Adjust radius |
| **Shift** *(while dragging)* | Precision mode: slow, fine adjustment |
| **Ctrl** *(while dragging)* | Snap to round increments |
| **`1`** | Round profile |
| **`2`** | Sharp profile |
| **`3`** | Soft profile |
| **`4`** | Tight profile |
| **`5`** | Chamfer profile |
| **`S`** | Toggle radius ↔ Chamfer Smooth (only useful when profile = Chamfer) |
| **Enter / Space / LMB-release** | Confirm |
| **Esc / RMB** | Cancel |

The viewport updates in real time, including across booleans and mirrors, so you see the fillet propagate through the entire modifier stack as you drag.

A [Smooth](../modifiers/smooth.md) modifier on the object rounds every edge to at least its radius, so a shape's own *Rounding* only shows where it is the larger of the two.

## See also

- [Blending](blending.md): fillets on modifier seams (`Ctrl+B` modal)
- [Profiles](profiles.md): all five fillet shapes explained
- [Interface: Gizmos](../interface/gizmos.md): viewport gizmos that open this modal