Available · version 2

Fillet

How to create and edit exact tangent fillets between lines and circular arcs in Cadivari.

Updated August 20263 min readCAD tools

Recommended test

Check the supported corner combinations, editability, and safety limits.

  1. Draw a 100 x 60 mm rectangle, choose Fillet, and hover one corner. The corner target should highlight clearly.
  2. Click the corner, enter 10.000 mm, and choose Apply fillet. The result should remain one closed five-segment contour.
  3. Undo, repeat, and choose All corners. Four equal tangent arcs should create a closed eight-segment contour.
  4. Draw two straight lines that share exactly one endpoint. Fillet their junction and confirm the two lines are trimmed to one tangent arc.
  5. Repeat with a joined line and arc, then with two joined arcs. Both source curves should trim to an exact tangent fillet.
  6. After applying a fillet, change Fillet R in Properties. The same fillet should rebuild while both neighbouring curves remain connected.
  7. Try a radius larger than the reported maximum. Cadivari should explain the limit and block the change.
  8. Undo and redo the result, then verify it can be selected as an ordinary connected path for CAM and exported to SVG or PDF.

01 · SELECT AND PREVIEW

Create a fillet

Choose Fillet from the CAD rail. Hover a rectangle corner or a junction shared by exactly two line or circular-arc entities, then click once to start. Moving the pointer adjusts the radius and shows the exact replacement curves and tangent arc before anything is stored.

Enter a millimetre value at any time. Click the canvas again, press Enter, or choose Apply fillet to commit the valid preview.

02 · RECTANGLES

Round one or all corners

Selected corner replaces only the highlighted rectangle corner. All corners applies the same radius to all four corners. Cadivari converts the rectangle into ordinary exact lines and circular arcs so the rounded outline behaves like any other connected CAD contour.

03 · ASSOCIATIVE EDITING

Change the radius later

The new fillet arc is selected after creation. Enter a new Fillet R value in Properties and Cadivari re-solves the corner, re-trims both supporting curves, and keeps the same fillet identity. This relationship is saved with the project and participates in undo and redo.

Dragging an arc handle deliberately releases the fillet relationship and turns it into an ordinary editable arc. This makes a direct geometry edit explicit instead of silently breaking tangency.

REFERENCE

Controls

HoverHighlight an eligible sharp corner
First clickSelect the corner and start the live preview
Pointer moveAdjust the radius visually
Radius fieldEnter an exact positive millimetre value
Second click / EnterApply a valid fillet
EscCancel the current preview
Ctrl + ZUndo the complete geometry replacement

NATIVE GEOMETRY

Ready for connected paths and CAM

A fillet is not stored as a visual effect. The source curves are trimmed and the corner becomes an exact arc with a compact associative definition. Connected-path analysis, save/open, SVG/PDF export, and CAM consume the same ordinary line-and-arc geometry shown on the canvas.

CURRENT SCOPE

Version 2 limits

  • Exact rectangles and unambiguous junctions made from exactly two line or circular-arc entities
  • Spline, ellipse, and arbitrary multi-segment fillets are not included yet
  • Branched junctions are deliberately rejected because the intended two curves are ambiguous
  • Each generated arc retains its own radius relationship; multi-corner radius groups are not included yet
  • Oversized radii are blocked before they can consume, collapse, or reverse an adjoining curve

A later extension can add spline fillets and multi-corner radius groups without changing the native connected-path result.