Voronoi-style vase with FDM-compatible overhangs. It can hold a bit of water, but it's obviously quite light so only use light flowers. Prints in one piece without supports.
While I originally used actual Voronoi, I found that it was too much work to make it printable. So this is actually based on a simple algorithm which takes overhangs into account while still retaining the Voronoi aesthetics.
Print without supports. Before printing make sure that you can print the Lattice Cube nicely in 50% scale. Otherwise this model will look bad or even fail.