Blending

Blending fillets the seam where two SDF expressions meet — booleans, mirrors, arrays, emboss/engrave. Set the radius on the modifier and the join becomes a smooth fillet without any extra geometry.

Smooth blend

Where blending lives

Modifier	Setting	Range
Boolean	Blend Radius	`0.0–10.0`, soft max `2.0`
Mirror	Mirror Blend	`0.0–2.0`, soft max `0.5`
Array (Line / Circle)	Smooth	`0.0–2.0`, soft max `0.5`
Emboss / Engrave	Blend Radius (outer) and Inner Radius (inner)	`0.0–10.0`

Boolean blend

The most common use of blending. Set the Blend Radius on a Boolean modifier and the seam between the two operands becomes a smooth fillet — including across Difference, Union, Intersect, and Slice.

Blend Radius — fillet radius
Blend Profile — Round / Sharp / Soft / Tight / Chamfer (see Profiles)
Blend Smooth (Chamfer only) — softens the chamfer’s edges
Material Blend — width multiplier for the color seam, independent of the geometry blend (see Profiles)

Mirror blend

Push Mirror Blend above zero to fillet the join across the mirror plane. Useful when modeling symmetric objects where you don’t want a sharp central seam.

Array blend

Both Linear and Circular Array have a Smooth parameter that fillets the join between adjacent copies. Pair it with a small Count and you get continuous flowing forms; pair it with a large Count and you get rippled surfaces.

Emboss / Engrave: dual blends

Emboss and Engrave have two independent blend radii:

Blend Radius (outer) — where the stamp meets the host surface
Inner Radius (inner) — the corner of the embossed feature itself

Set them to different values and profiles for sharp logos with soft outer transitions, or smooth recesses with sharp inner edges.

Workflow

Add the modifier (Boolean, Mirror, Array, Emboss).
Locate the Blend Radius / Blend / Smooth parameter.
Drag it up — the seam smooths in real time.
Pick a profile if you want something other than Round.
For Boolean, optionally tweak Material Blend to control color seam width.

Adjust modal (`Ctrl + B`)

Press Ctrl + B over an object with a boolean to drag its blend radius live. You can also click the blend gizmo dot in the viewport to enter the same modal — see Interface: Gizmos.

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 / LMB-release	Confirm
Esc / RMB	Cancel

The viewport updates in real time, so you see the seam smooth out across booleans, mirrors, arrays, and emboss/engrave as you drag.