The evolution of the digital curve: from shipbuilding spline to the diffusion of NURBS, subdivision surface and t-splines as tools for architectural design

In this article, we will follow the history of splines, digital methods that have characterized the architectural design process since the last decade of the twentieth century. We will describe their evolutions since the beginning as analogical tools for boat construction in the eighteenth century, to its passage to digital within the automotive industry. Then the relationship with the aerospace industry, and the evolution which from digital animation, have led nurbs, subdivision surfaces and t-splines to become everyday computational tools within architecture workflow. Recent developments on t-splines, following their acquisition by Autodesk, will lead us to a reflection on the relationship between software houses, which develop tools, and architects, who are now dependent on them. Therefore, we will consider the need to develop open-source methods, as Pixar did with Opensubdiv, as knowledge and responsibility shared solution.