Extrude

Click any enclosed area of a sketch — a solid island, the ring between two circles, a pocket formed by overlapping shapes — and just that region is selected, holes and all. There's no guessing which pieces an even/odd fill rule would grab. The selection is remembered by where you clicked, so if you later reshape the sketch the extrude re-finds the region under that point and rebuilds; if your click no longer lands inside anything, the feature flags itself for a quick re-pick instead of failing silently.

The picked boundary reproduces your sketch exactly: every arc keeps its drawn center and radius to full precision, straight edges stay straight, and tangent junctions are seamless — no hidden micro-edges on the walls. That's what makes downstream chamfers and fillets flow cleanly around arc-heavy profiles like gear teeth and rounded slots, and it holds for regions bounded by exploded text and imported geometry too. Picking several touching regions merges them just as exactly, while separate islands still become separate bodies.

You don't always need a sketch — this is the fastest way to extend a feature straight on a solid, where dropping to a sketch would be fiddly. Click a flat face on an existing solid and drag: any holes in the face come straight through, and just like a sketch extrude it auto-detects the operation — drag outward to add a boss (Join), drag into the material to sink a pocket (Cut), or choose New Body — with the choice always overridable. A joined boss merges flush into the part with no leftover seam line where its walls continue the parent. The extrude stays linked to that face, so when the source part changes it rebuilds with it.

The Distance field takes expressions and explicit units (0.5in, 12mm) and honors your preferred units. Or skip typing entirely: drag the arrow gizmo in the viewport, or click an aligned face on another body and the distance snaps exactly flush to it. Click the far face of a body and JetCad3 nudges the depth slightly past it, so a cut clears all the way through cleanly.

The moment the preview intersects an existing body, an Operation dropdown appears: Cut subtracts, Join fuses, New Body keeps an independent solid. JetCad3 pre-selects the likely intent — a profile pushed clean through a plate reads as a through-hole and defaults to Cut — and auto-detection keeps flipping between Cut and Join as you drag the arrow through material. The moment you pick an operation yourself, your choice sticks for the rest of the operation. Editing an existing Cut or Join re-opens the dialog with the saved operation already selected, and the translucent red cut preview shows exactly what will be removed before you press OK. See Boolean Operations for the multi-body picture.

Enter a Twist angle and the profile rotates progressively as it travels, holes included — twisted balusters, decorative pickets, and auger-like forms straight from a flat sketch. A Turns box sits right below it and stays in step: type 2 turns and Twist reads 720°, type 90° and Turns shows 0.25 — enter whichever way you think. Each region twists about the center of its own footprint, bottom clamped and top rotating, so a shape drawn away from the sketch origin twists in place instead of corkscrewing sideways — and the preview matches exactly what commits.

Set a Draft Angle and the extrude's walls lean evenly as they rise: a positive angle grows the far end outward, a negative angle pulls it in. It works with every operation — tapered bosses (Join), drafted pockets (Cut), and standalone tapered bodies alike. When the profile has holes, a Hole Draft choice sets whether they taper with the outline (everything grows or shrinks together) or inverted, mold-style (all walls share one pull direction, so a drafted plug and its drafted hole both release from a mold); the choice is remembered. If the angle is too steep for the profile — the far face would vanish — a plain red note appears under the input and OK holds until the value works. An extrude takes a twist or a draft angle: setting one clears the other.