Parametric design: form generated by algorithms and parameters rather than drawn by hand. Tools: Grasshopper (Rhino), Dynamo (Revit), Processing, Maya. Characteristics: double-curved surfaces, complex geometry, organic flowing forms, responsive to environmental data (solar, wind, view). Fabrication: CNC milling, robotic cutting, 3D printing, parametric formwork. Famous: Heydar Aliyev Center Baku (Hadid), Beijing National Aquatics Center (PTW), Morpheus Hotel Macau (Hadid). Materials: GFRC, ETFE, aluminum panels, parametric timber (gridshell). Cost: $400-$1500+/sf (custom fabrication for every panel). Growing: computational design increasingly common even for conventional buildings (facade optimization, structural optimization).