"Orb" is an algorithmic animation piece consisting of a collection of decorative objects. Gilded ornamental patterns on the surface of the objects were rendered as procedural bump textures generated with metaballs. Specifically, an original metaball algorithm that performs a threshold-detection process for all metaballs was used in this work. The algorithm can generate complicated and unexpected forms in which the curves of each metaball emerge partially. Metaballs with regular polygonal density distribution such as triangular or hexagonal were also used.