Smooth Corners

Smooth Corners is one-drop print finishing for a whole part. Apply it to a body — no face picking, the input is the entire solid — and it chamfers every edge parallel to the build plate at 45 degrees while rounding every vertical edge with a fillet. Two different treatments, because the plate cares about the difference: 45 degrees is the classic self-supporting angle, so the bottom perimeter needs no elephant-foot compensation and the top break has no sharp lip, while a vertical round prints cleanly at any radius and spreads stress instead of concentrating it at a corner. The clever part is that it is re-runnable. Both groups gate on the edge's fold angle — the angle between its two adjacent faces — so an edge that has already been smoothed is not smoothed again. The border of a previous 45-degree chamfer sits at 135 degrees and a fillet seam sits near 180, and both are excluded from the chamfer group, so running the object twice is a clean no-op rather than an error or a compounding blend. The fillet group is deliberately more permissive: a vertical edge at 135 degrees, such as the border left by chamfering a vertical corner, still gets rounded, because rounding over an already-roughed part is exactly the use case. Chamfer and Fillet set the two sizes, and Chamfer edge tolerance widens the window around 90 degrees for parts with sloped walls whose horizontal edges do not fold at a right angle. A few things it leaves alone by design: circular rims, such as a bore opening or a cylinder cap, have no axis to classify and are untouched, and edges with a curved neighbour face have no measurable fold angle and are skipped. Also make sure both blends fit — on a plate of thickness t the chamfer consumes twice its size in height, and a blend that swallows a whole face will be rejected.