Amsterdam based artist Berndnaut Smilde is known for his cloud installations. After the TIME magazine listed them as one of the Top 10 inventions of 2012, people's fascination with Smilde's work became widespread. The latest cloud installation, called Nimbus Green Room, took place this summer at the Veterans Building in downtown San Francisco. Here is how artist comments on this project:

It's not so much about the shape of the cloud but about placing it out of its natural context. It brings duality, because you can't really grasp how to interpret the situation you are viewing. People have always had strong metaphysical connections to clouds as they symbolize the ominous.

Even though the clouds look spontaneous, each takes meticulous preparation. The room has to have the right temperature and humidity for the effect to last several seconds. Probably the most fleeting installation in history, Numbus creates a profound impact. And each chosen room adds new context and atmosphere. Watch the film about the Nimbus project to see it in the making.