The Cubists invented multiple-point perspective early in the 20th century; Braques' violin paintings and Picasso's landscapes and portraits are some of the most memorable examples. There is more than one way to see a woman or the world, their paintings seem to say.

Beginning in the 1970s, David Hockney developed the idea further in his photographic collages, patching together overlapping prints taken from multiple vantage points to form Cubist panoramas of a Parisian square, a California desert, a Yosemite Valley river.

Now quilters have picked up the thread with "slice" quilts, which have their roots in a single photograph, often a landscape. The end product, however, is a fractured image that appears to come from different viewpoints.

In a way, it does; the photograph is cut apart and each collaborator is given a different slice to enlarge and interpret. The quilters work independently without communication until it's time to assemble the work.

Such is the genesis of "Pittsburgh," a slice quilt by four members of the Three Rivers Quilters guild. It will be on display at the group's annual Three Rivers Quilt Show to be held Thursday through Saturday at the IBEW Circuit Center, 5 Hot Metal St., South Side.

The "Pittsburgh" quilt's vantage point seems to have been a high point in the Allegheny Landing sculpture park on the North Shore. The Andy Warhol (Seventh Street) Bridge spans the river above Ned Smyth's columnar sculpture, "Mythic Source." The convention center, Gulf and U.S. Steel towers, Koppers Building and Regional Enterprise Tower (ex-Alcoa Building) are among Downtown's recognizable landmarks. But the landscape is disjointed, familiar yet broken.

Slice quilts have been around at least since the late 1990s; the technique is a natural for quilters, who are used to collaborations on album and friendship quilts. Landscape quilts, sliced or not, have grown in popularity, too, in recent years, with the introduction of fun trompe l'oeil fabrics depicting bricks, clouds, grass, stones, water and other natural features.

But only one of the slices uses a landscape fabric -- for Allegheny River water -- in the "Pittsburgh" quilt. No shortcuts for these gals.

Finding the right fabric, machine stitch and assembly technique -- applique mostly -- was part of the challenge, but the most difficult thing was getting the bridge and its cables into the right perspective, said Nancy Reigel of Whitehall, who organized the project. Pat Griffith of Bethel Park, Anabeth Dollins of Mt. Lebanon and Camille Autieri of Carnegie also participated.

Another guild member, Lila Mason of Upper St. Clair, took the photograph as well as one of Ketchikan, Alaska, which another group of Three Rivers quilters used to make a slice quilt that also will be on view at the show.

While the nonprofit Three Rivers Quilters guild has an encompassing name, most of its 74 members live in the South Hills. Pittsburgh enjoys an active quilting community, with guilds at all of the compass points.

The Three Rivers show, among the region's largest, has 147 entries this year, "the most we've ever gotten," said Janet Kaiser, whose vibrant "Afterglow" quilt was machine-pieced and hand-quilted from a single piece of batik fabric that reminded her of a Lake Michigan sunset.

Most works in the show are machine-pieced and machine-quilted.

"The hand quilters like myself are kind of in a minority," Mrs. Kaiser said.

This year's theme is Nine-Patch Quilts, but most entries don't adhere to it; the annual theme constitutes two -- for large and small nine-patch quilts -- of 13 categories.

"Nine-patch is a very basic patch you can take off with," she said. "It's just a tribute to the beginnings of quilting, really, because it's such an old patch. We have some very innovative approaches" in the show.

"The creative aspect of quilting has been very important to women," Mrs. Kaiser said. "But I think the most important thing is that quilting in all its phases is very therapeutic. You can belong to a quilt group and you share your designs and projects but also part of your lives with these women. You become very close friends. I think it holds true for young people coming into quilting. It's one-on-one; it's not by e-mail or over the phone."

Anyone could enter this open show, and quilts come from as far away as Washington state. A committee of Three Rivers guild members serves as the jury. About 1,500 people attended last year. The show will include vendors, demonstrations, a cafe and Granny's Attic sale of donated fabric and quilt books.

"Our quilt show is just the right size, not so huge you can't visit it in a day. You can see some beautiful quilts made by beginners as well as very advanced artists. Our show is a mix of art quilts and quilts for the bed. It just celebrates quilt-making," Mrs. Kaiser said. "We reward the winners with cash prizes and ribbons."

Doug Oster writes a blog, "Growing With Doug," exclusively at PG+, a members-only web site of the Pittsburgh Post-Gazette. Our introduction to PG+ gives you all the details.