Residual Forms

Objects · SCI-Arc · 2023

How much of a sculpture survives the trip through a machine?

Residual Forms starts from a caryatid, a column carved as a standing figure, where the structure and the body are the same object. The choice was fairly arbitrary. It was useful because it holds two readings at once. The pipeline that follows takes the figure out and leaves the column.

Watch: The whole process in ninety seconds.

Image to object

Each column starts from a photograph of a person, which Stable Diffusion turns into a statue. PIFuHD reconstructs a body from the flat image, then Houdini inflates the mesh and takes its convex hull. A convex hull has no concavities, so the body comes back as one volume and the figure is gone. An ABB arm cuts what remains from a three-foot polystyrene blank with a hot wire.

Watch: Inflate, then convex hull. Two operations, and the second one is not reversible.

Object to path

Painting runs the other way. The wire leaves the foam and the file as different objects, so the brush can only work from the foam. A RealSense camera scans the surface into the arm's coordinates. A Processing sketch reads contours off that scan and turns them turns them into hatch angle, pressure and five colors lifted from a still life, then writes the robot code.

Residue

The reconstruction loses the face, the hull takes the body, and the wire takes the rest of the detail. What comes out is an upright form with a slab on top and a base underneath. A plinth.

Shown at SCI-Arc in 2023, in a studio led by M. Casey Rehm, alongside the rest of the cohort's plinths. The two halves of the pipeline never exchange a file. The geometry side hands over a physical object, the painting side starts by scanning it, and nothing from the digital model reaches the brush.