Bryce does not have primitives with bevelled edges, but you can easily simulate this. For a cube, you need 8 spheres (corners), 12 cylinders (ribs) and 3 cubes (sides), as show in figure 2 above). The degree of rounding is determined by the diameter of the spheres and cylinders. Similarly, for a cylinder with bevelled edges you need 2 cylinders and two of those torus thingies. Cones is a bit more of a puzzle and also requires a few booleans.

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