Extrusion is the most-used operation in all of CAD: take a closed 2D profile and push it along a straight line to create volume. Here's how to do it well, using OpenShape3D's Shapr3D-style workflow as the example.

The basic extrude

  1. Draw a closed profile on a plane or face — closed loops show a fill.
  2. Tap the fill to arm it, then either drag the pull arrow for a live, interactive extrude, or open the numeric bar and type the exact distance.
  3. Commit (tap empty space or the Extrude button). You now have a solid body.

Holes for free: nested profiles

Draw a circle inside your rectangle before extruding, and the extrusion treats it as a hole — no separate cut needed. Any level of nesting works; outer boundaries add, inner ones subtract, alternating inward.

Multi-profile extrudes

Arm several fills at once and they extrude together to the same height as one body — handy for text, logos, and bolt patterns.

Extents and direction

  • One-sided (default): the profile sweeps in one direction by your distance.
  • Symmetric: grows both ways — per-side distance, twice the total — keeping the sketch plane at the middle. Great for parts you'll mirror or center.
  • Negative drag: pull the other way to extrude in the opposite direction, or into an existing body to cut.

Boolean result options

When your extrusion touches existing bodies, the result mode decides what happens:

  • Auto — pull away to union, push in to subtract (the direct-modeling default).
  • New Body — keep the extrusion separate even if it overlaps.
  • Union / Subtract / Intersect — force a specific boolean regardless of direction.

OpenShape3D shows a boolean badge (Auto | New Body | Union | Subtract | Intersect) during the extrude, plus live validity feedback — the pull arrow turns red if the pending result would fail.

Troubleshooting

  • No fill appears: the profile isn't closed, or your shape is construction geometry (dashed). Close the gap or convert to regular lines.
  • Extrude fails at commit: usually self-intersecting profiles; simplify overlapping segments with Trim.
  • Wrong thing got cut: check the boolean badge wasn't left on Subtract from a previous operation.