Recommended test
Offset a rounded outline and compare the original and result before extrusion.
- In Sketch mode, draw a closed profile using lines and rounded corners.
- Choose Offset, click the boundary and move the pointer to preview an inward or outward distance.
- Enter a modest distance and press Enter or Set offset.
- Hide dimensions if needed, inspect every corner, then finish the sketch and test a shallow extrusion.
Use guides as references
Guides establish alignment or a centreline without forming a solid boundary. Select a guide to edit its position or offset. Use Mirror guide to make the selected guide the mirror line, then inspect the reflected drawing as you construct the profile. Turn the mirror guide off to continue independently.
Convert a guide to ordinary sketch geometry when it must become part of a closed boundary. Keep helpful centre references until the profile is finished.
The sketch header also switches between Normal geometry and Construction geometry. Construction lines, circles and arcs remain useful for snapping and relationships but do not close an extrusion region.
Offset a closed outline
- Choose Offset in Sketch mode.
- Click the required closed boundary. Picking a straight section of a filleted outline selects the connected outline.
- Move the pointer to preview the distance, or type an exact value.
- Click again, press Enter or choose Set offset to place it.
The second click fixes the distance while any remaining calculation finishes. Mouse movement does not overwrite a typed value. Escape cancels the pending offset.
Distance is measured perpendicular to the source boundary. Straight sections remain straight, circular sections stay curved, and spline outlines produce editable curved pieces suitable for later Push/Pull, Revolve or Sweep. The original outline remains available.
Check tight corners
An inward offset can close a narrow neck or create pointed corners where parallel curves meet. A cusp may be the expected geometric result of that distance. Reduce the distance if you want a smoother remaining outline.
Offsets that collapse, split into several disconnected regions or cannot be fitted accurately are rejected. Simplify the outline or use a smaller distance. Local folds are trimmed where supported; this does not make every self-intersecting source valid.
When several nearby offsets overlap on screen, zoom in and check which source highlights before placing the next one. Existing offsets are independent geometry: changing the original spline does not regenerate them.
Keep the intended region clear
Construction geometry and ordinary boundaries can look similar at a distance. Review the region highlight before creating a body. Use sketch constraints for lasting dimensional relationships and visibility controls to keep finished sketches readable.