Flowing shapes, smooth blends and other organic tools

Sculpting (see Sculpting organic shapes) is one way to make an organic form. A few more steps cover the rest. Every one of them ends as a normal, closed solid, so holes, fillets, shells, exports, the printability check, slicing and simulation work on the result like on any other body. Ask the agent in plain words, or add them from the Recipe.

Flowing shape

A smooth body through cross-sections placed along a path: bottles, vases, ducts, handles, lamp shades.

• Path — a straight line, a smooth curve through points, or a 3D path / sketch from an earlier step.
• Sections — each at a position along the path (0 = start … 1 = end): a circle, ellipse or rounded rectangle, a smooth curve through points, or a sketch. A section can be turned around the path.
• Smooth (default) flows through the sections with no bumps or kinks; Straight goes in straight pieces from one section to the next (flat sides between square sections).
• Wall — make it hollow with this wall thickness. With open ends (start, end or both) it becomes a tube, a cup or a shade.

The sections stay upright as the path bends — they don't twist — and on a curved path the shape follows the curve instead of cutting its corners.

Tip: an open flowing shape without a wall is a thin skin. Give it a wall, add a Thicken step, or Fill its opening before printing.

Smooth blend

A seamless transition along edges — where a handle meets a body, along the edge of a lid — softer than a fillet. A fillet is a round: the reflection jumps where it meets the flat face. A smooth blend matches the curvature of the faces on both sides, so light flows over it without a break (check with Check smoothness).

• Size — how far the blend reaches onto each side (mm).
• Smoothness — curvature (default, the premium look), tangent (a regular rounding) or touch (a bevel: the surfaces just meet).

Smooth it in the smoothness check adds one for you. If the curvature-smooth version can't be built on some edges — for example a loop of edges that turns sharp corners, or a closed loop all the way around a post — the step keeps a regular rounding there and says so in the Recipe, so you never get a broken part. The smoothness check then accepts that rounding: it doesn't list its edges as places where reflections jump, because another blend can't do better there.

Fill an opening

Closes a hole or an open end with a smooth patch that matches the surfaces around it — touch, tangent (default) or curvature — with an optional bulge (+ outward, − inward) in the middle. Pick every edge around the opening. On an open skin the patch makes it a closed solid again; on a solid, the hole is filled with material, flush with the surface around it (a through hole is closed at both ends).

Thicken

Turns a skin into a printable wall of a set thickness: inward, outward or both ways. Without a face selection it thickens the open skin of the body; with faces picked from a solid, only those faces are kept, as a wall (a cover cut from a sculpted shape, for instance).

Flat base

Organic shapes often touch the print bed at a single point. Flat base cuts a little off the lowest side — 1 mm by default — leaving a flat face to sit on. The printability check suggests it (No flat base) and its Fix adds the step with a depth that gives the part a stable footprint.

Start from…

New sculpted bodies can start from a ready shape — blob, capsule, soft cube, ring, bottle, mouse shell, handle loop or organic stand — sized to the finished body, not the cage.

For CAD users: sculpted bodies are exact B-reps: bicubic B-spline patches fitted to the Catmull–Clark limit surface — exact (G2) in regular regions, tangent-continuous to within a fraction of a degree around extraordinary points (measured ≤ 0.2°) — sewn into a validated solid. Flowing shapes are lofts through the sections along a rotation-minimising frame, C2 across sections. Smooth blends rebuild the rolling-ball band as N-sided plate patches constrained G2 to their neighbours. Pro terms shows these names in the app.