Digitally-Assisted Stone Carving

As part of the ongoing maintenance of the East Block, PSPC, identified a sandstone relief sculpture for replacement. The sculpture features an owl among thistles carved into a 1725mm x 1120mm piece of Berea sandstone. It is found on the north façade — above the entrance to the courtyard of the 1910 wing. CIMS was invited to collaborate with the Dominion Sculptor (Phil White) and HCS on the task of creating a replacement.

First, the relief sculpture was digitized using photogrammetry. A polygon mesh model of the relief sculpture was generated from the photogrammetric information. From that digital model, a copy of the sculpture was milled from high-density polyurethane foam using the 3-axis CNC router at the Carleton University School of Architecture. The foam maquette, taking the place of a traditional plaster copy, served as the basis for the Dominion Sculptor to rebuild the damaged areas with modelling clay. With the modelling clay-overlay applied, the maquette was digitized again using a close-range laser scanner. From this second digital model, the relief sculpture was milled in sandstone using a 6-axis industrial robot. Finally, the Dominion Sculptor added remaining details and textures using traditional stone carving tools.