3D printing IU landmarks in honor of the IU Bicentennial: IU News

The Showalter Fountain – designed by Robert Laurent, IU Professor of Fine Arts from 1942-1960, and completed in 1961 – is more than the memorable centerpiece of IU's Fine Arts Square; it's the source of multiple campus legends and traditions, including one in which newly-minted Hoosier grads take a quick dip under the goddess Venus's gaze. Scott Birch, Manager of IU's Advanced Visualization Lab, also found it to be one of the most challenging art pieces on the Bloomington campus to digitize via photogrammetry. Photogrammetry is a technique that calculates an object's geometry using a series of overlapping photographs. The data from the photographs allow for the creation of a fully-textured 3D model, resulting in a digital replica with sub-centimeter accuracy and a photorealistic appearance.

The UITS Advanced Visualization Lab specializes in photogrammetry and has created a robust library of IU artifacts large and small, so they were a natural go-to group when the Bicentennial Bus needed interactive resources. The lab produced 3D printed replicas, an interactive touchscreen, and virtual reality, all featuring popular important artifacts, spaces, and places for the bus's exhibits. When the list of dozens of sculptures, statues, and objets d’art was pared and curated, the Showalter Fountain remained a finalist, a key piece of IU history that would be 3D-printed and featured in a Bicentennial Bus display.

The completed 3D print of the Showalter Fountain. Image courtesy of Scott Birch.

The process of digitizing a large outdoor sculpture proved to be complicated. Photogrammetry often deals with small objects and sculptures photographed indoors under a tightly controlled temperature and lighting environment. Birch found himself in the opposite situation as he attempted to gather essential data in Fine Arts Square on a bustling, hot summer afternoon. When he learned of a rare two-hour window in which the fountains would be idle, Birch donned his swimwear and submerged himself in the fountain, taking thousands of close-up photos of the bronze figures from all angles close and far. For best results, he waited until the sun ducked behind the clouds, reducing the shadows that can hamstring the photogrammetric processing, and snapped as many photos as possible before the blazing rays returned.

After the photos were taken, they were organized by object and optimized for the intensive software algorithms that would be calculated by a high-performance computing cluster, transforming pixels into points and polygons. A quick post-processing of the new 3D models cleaned and resized the sculptures into miniature recreations that were 3D printed in a metal that closely matches the original. To make this possible, the printer deposits tiny drops of glue onto layers of stainless steel powder, layer by layer until the print is complete.

3D prints of the five fish that surround Venus. Image courtesy of Scott Birch.

The fountain's base was created through a similar process; it was 3D printed in full-color sandstone by depositing a binder material onto a bed of gypsum powder, again, layer by layer. The sandstone is a brittle material, but one that allows for great detail in art sculptures, figurines, architecture, or terrain models.

Once the pieces were printed, the fountain was put together piece by piece, and to achieve the effect of water in the fountain, a clear resin epoxy was mixed together and poured into the fountain base. After a 24-hour cure, the resin hardens to a solid plastic layer with the visual characteristics of water, including reflective and refractive properties.

How did this all turn out? Did it work as expected? You will just have to visit the Bicentennial Bus to see for yourself!