A carefully designed piece of awning set to grace the future Transbay Transit Center in downtown San Francisco was unveiled today.

Democratic Minority Leader Nancy Pelosi, D-San Francisco, California Democratic Party chairman John Burton and San Francisco Supervisor Jane Kim joined members of the Transbay Joint Power Authority at the site of the future center located near First and Mission streets.

The ceremony marked the start of the final phase of construction on the transit center, which is slated to open sometime in late 2017.

The awning has a distinct pattern discovered by Oxford University professor Roger Penrose. The Penrose pattern, as it’s called, is a rhombus tiling pattern that can be extended infinitely without repeating itself.

Penrose has allowed the joint powers authority to use the pattern at no cost.

Once installed around the transit center, the roughly 3,000-foot-long and 44-foot-tall awning will create a lace-like screen that wraps around the entire four-block exterior. The perforated design will leave 37 percent of the panel surface open in order to allow light and air to enter the building.

Pieces of the awning will be installed in the coming weeks, with the final panel set to be placed in early 2017, joint powers authority officials said.

In addition to the awning, the transit center will also include a 5.4-acre rooftop park with an open-air amphitheater, garden, trails, a children’s play space, and a restaurant and café.

The future transit center is planned to connect 11 transit systems, including Caltrain and a future proposed high-speed rail line.

Via Bay City News