Stereotomy, the science of cutting solids. 

Stereotomy can also be understood as stonecutting, at the end, stone is a solid. This section shows drawings and animations of how the stone was carved to construct the great vaults of the Mexican churches of Yanhuitlan, Teposcolula and Coixtlahuaca. 

In addition to the analysis of the underlying geometry governing the shape of the vaults, the analysis involved the recreation of the stone-carving solutions necessary to achieve the construction of the stone structures. 3D animations showing these solutions. The study of the stereotomy is crucial for the understanding of the technology transfer that took place in this part of the world during the sixteenth century. Stereotomy also reveals the level of sophistication of the carving solutions for each piece of the vault in order to guarantee the structural stability of the vault. In addition, stereotomy studies allow to understand with more detail the skills that the indigenous people of Mexico had to learn while opening doors for comparing with contemporary vaults in Europe and the rest of the world. Finally, the same stereotomy studies help to create hypothesis regarding the carving procedures that masons had to follow in order to carve each one of these complex pieces of stone which also brings to light the amount of material necessary to built each structure and the size of the pieces to be obtained from the quarry. 

The process of carving generally speaking starts by regularizing the stone that has been obtained from the quarry. Once the piece is regular and has a flat surface, the template of the piece on horizontal position is placed on that flat surface and drawn on the stone. Once the bed-joints are carved a template with the molding of the ribs is placed on each arm of the piece. This molding silhouette of the rib serves to carve out the arms until they converge with the drum of the keystone. If the keystone has a seal, then it is carved either before or after the piece has been placed on the vault.