Autodesk Research is doing work on "generative design", which creates shapes the way nature would. The software is given some simple constraints -- some physical attachment points and strength/weight targets -- and then it "evolves" a shape that is nothing like the one a human would design. See this article for more:
Structures built in generative design “tend to have a highly complex, sometimes organic shape,” Erin Bradner, a research scientist from Autodesk Research, says. That’s because generative design uses algorithms to calculate the best design for a product based on both the functionality the designer wants, and the environmental constraints and forces acting on the object. With fewer straight lines and planes than traditional computer modeling, the process “is more akin to something like bone growth,” Bradner says.
Here are some photos of the 3D print in real life. It's incredibly strong!