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Reference

EXTRUDE in AutoCAD

How AutoCAD's EXTRUDE (EXT) turns a closed 2D profile into a 3D solid, prompt by prompt: the height, Direction, Taper angle. Try it free in your browser.

EXTRUDE turns closed 2D profiles into 3D solids, each pulled straight out of its plane by the height you give. Select the profiles — circles, ellipses, closed polylines or splines, regions — and press Enter, then type the height or show it with a point; the last height is the next run's default. Each profile becomes a solid of its own, on the current layer, and is erased, as DELOBJ says by default. The whole command is one step that Undo takes back.

MellowCAD's 3D is solids only, and still partial: an open profile, which AutoCAD turns into a surface, gets Cannot sweep or extrude an object of this type. and is removed from the selection.

At the command line

The engine draws it and writes its history as you would type it: the prompts in AutoCAD 2027's order, with the same option letters.

A closed L-shaped polyline extruded 20 into a solid, then seen from the south-east in the Hidden visual style.
  1. Command: EXTRUDE
  2. Current wire frame density: ISOLINES=4, Closed profiles creation mode = Solid
  3. Select objects to extrude or [MOde]: 1 found
  4. Select objects to extrude or [MOde]:
  5. Specify height of extrusion or [Direction/Path/Taper angle/Expression]: 20
  6. Command: -VIEW
  7. Enter an option [Orthographic]: SEI
  8. Command: ZOOM
  9. Specify corner of window, enter a scale factor (nX or nXP), or [All/Extents/Previous/Scale/Window/Object]: 0.8x
A closed L-shaped polyline extruded 20 into a solid, then seen from the south-east in the Hidden visual style.

Options

MOde (MO)

Asks for SOlid or SUrface. SOlid is the default and the one there is: with no surface objects yet, SUrface is refused.

Direction (D)

Instead of a height, two points give the direction and the length: the profiles are extruded along that line, slanted if it is. A direction lying in the profile's plane gets Extrude direction is parallel to plane of sweep curve., and the command ends.

Path (P)

Listed, as in AutoCAD, but not built: choosing it is refused, and the height is asked again.

Taper angle (T)

Asks for an angle between −90 and 90 degrees, then the height again: a positive angle narrows the solid as it rises, a negative one widens it. A circle that closes before the height ends in a point, a cone; a profile the taper cannot take makes nothing.

Expression (E)

The height as an expression: 2*3 is 6. Only arithmetic so far.

What it does not do yet

Path, the sweep along a path. SUrface mode and open profiles, which AutoCAD makes surfaces of: there are no surface objects yet. The faces of solids and the areas a click finds inside objects, which PRESSPULL takes. A taper on an ellipse, a spline, or an arc meeting the next segment at a corner. Expression's parameters and functions. EXPLODE of an extruded solid with curved sides, which AutoCAD turns into surfaces and regions. Its grips, and its height and taper angle edited in the Properties palette.

What it does and still lacks, in detail (in English)

Questions

What is the shortcut for EXTRUDE in AutoCAD?

EXT, then Enter or Space. The full name works too, and _EXTRUDE in any language of AutoCAD.

How do I extrude a 2D drawing into 3D?

Draw the outline as one closed object — a closed polyline, a circle, or a region — run EXTRUDE, select it, press Enter and type the height. From above, a solid looks like its outline: turn the view with the ViewCube, or -VIEW and SEIso, to see it in 3D.

Why does EXTRUDE not make a solid?

The profile is open, or crosses itself. A line, an arc or an open polyline makes a surface in AutoCAD, and MellowCAD has none yet: EXTRUDE says Cannot sweep or extrude an object of this type. and removes them from the selection; a profile that crosses itself gets Cannot sweep or extrude a self-intersecting curve., and is removed too. Join the pieces with JOIN, make a region of them with REGION, or click inside them with PRESSPULL.

How do I extrude a shape with a hole?

Make one region of it: REGION on the outline and the hole, then SUBTRACT the hole's region from the outline's. Extrude that region, and the hole runs through the solid. Or run PRESSPULL and click between the outline and the hole.

How do I extrude along a path?

Not yet: Path is listed but refused, and SWEEP is not built. Direction extrudes along the straight line between two points.

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