For organic modeling
Smooth blends
Switch a group from Sharp to Blended so parts melt together with a rounded, clay-like join instead of crisp boolean edges.
Smooth blends let a group fuse its parts with soft, rounded seams instead of hard edges. Internally the group switches from exact mesh booleans to a signed-distance field, so where two shapes meet you get a fillet-like transition — the classic "melted clay" look — across the whole group at once.
Reach for this for organic forms, ergonomic handles, fillets you'd otherwise model by hand, and skeleton/bone-style bodies where you want limbs to flow into one another. It's a per-group setting, so the same parts can read as crisp or smooth just by flipping a dropdown.
How to use it
Group the parts
Build and the parts you want to blend (smooth blending is a group property, so the shapes must be grouped first).
Open the Combine section
Select the group and open the Combine section of the Properties panel.
Set Style to Blended
Set the Style dropdown to Blended. (The default is Sharp; a Loft option also appears here when the group qualifies.)
Raise the blend size
Drag the Blend size (mm) slider up from 0. This is the rounding radius where shapes touch — 0 means no rounding, and bigger numbers melt the shapes together more.
Keep flush faces flat
If you want flush faces to stay flat, turn on Blend only on overlap. This switch appears once Blend size is above 0.
Tune the detail
Tune the Detail (mm) slider if the surface looks too coarse or rebuilds too slowly — smaller is sharper but slower.
Tips
- Blending only exists on a group set to Blended — there's no standalone "smooth" command. Two ungrouped parts can't blend.
- Blend only on overlap rounds only where shapes actually overlap; parts that merely touch face-to-face connect flat, with no bulge at the seam. With it off, every seam is rounded and a small ridge can appear where flush faces meet.
- The Blend only on overlap switch is hidden until Blend size is greater than 0 — a zero-radius blend is just a hard union.
- Blended mode is fastest with math-defined primitives (Box, Sphere, Cylinder, and friends). If the group warns that some shapes "have no math formula", rebuilds are slower — swap those for basic shapes.
- Multicolor works in Blended mode too, so coloured parts keep their colours through the blend.
Try it in your browser
Open CubbyCAD and put Smooth blends to work — it runs in the browser, no install.