BeveledPolyhedron

BeveledPolyhedron[poly] gives the beveled polyhedron of poly by beveling each edge.

BeveledPolyhedron[poly, l] bevels the polyhedron by a length ratio l at its edges.

Examples

Bevel a cube:

Graphics3D[BeveledPolyhedron[Cube[]]]

With custom bevel ratio:

Graphics3D[BeveledPolyhedron[Tetrahedron[], 0.3]]

Please visit the official Wolfram Language Reference for more details.