Module sheet 

Rounds on sheets: where two faces of an open shell meet at an edge, and in the corner between two faces of separate shapes.

A solid’s fillet is a wedge cut away or fused on. A sheet has no volume for a boolean to take a wedge from, so here the faces are rebuilt: each face the ball touches loses the strip between the corner and its line of contact, its boundary is re-routed along that line, and the round shares the edge there with it. The shared edges are built once and used by both faces, so the result’s topology is exact by construction rather than sewn within a tolerance.

Between two planes the rolling ball’s envelope is a cylinder whose axis is where the two planes’ offsets meet, and the lines of contact are straight: every curve and every trim here is closed-form. Curved faces are rounded in sheet_curved: exactly where the supports share a direction or an axis, marched otherwise.

Functions

fillet_faces

Round the corner between two faces of separate shapes with a rolling ball of radius.

fillet_sheet_edges

Round edges of a sheet where two of its faces meet, with a rolling ball of radius.