ST. PETERSBURG ó Curious to see what Tampa-born artist Janet Echelman has envisioned for the Pier District?On Tuesday Echelman, whose studios are in Massachusetts, unveiled images of the parasol-inspired, LED-illuminated sculpture that will float above Spa Beach.The net sculpture, made of the same material that is used for astronautsí spacesuits, and anchored on pylons, will cost nearly $3 million. Onlookers should expect "gentle billowing" on an average day, the internationally renowned artist said. The piece is expected to span about 390 feet. It will rise at least 15 feet from the ground, Echelman said in her telephone presentation to the Public Arts Commission. Her pieces are built so people canít touch them, either by jumping up to reach them, or by using a hockey stick, she said. A member of the arts commission wondered about fishing poles, something that Echelman said she will certainly consider. There were also questions about soccer balls being caught in the net sculpture, something that has happened once, the artist said. "We were very impressed with that," she joked, but added that a soccer ball is easily dislodged by maintenance employees. Tennis balls and baseballs will simply fall through, she said.The renderings she presented depicted views in the daytime and at night, when the sculpture is illuminated. Shown are views from Vinoy Park and the Museum of Fine Arts.