Recompose Grammars for Procedural Architecture

We present the novel grammar language Recomp for the procedural modeling of architecture. In grammar-based approaches, the procedural refinement process is based on shape subdivisions. This process of decomposition results in disconnected subparts, which not only restricts the geometric expressiveness but also limits the control over an appropriate shape granularity needed to coordinate design decisions. Recomp overcomes these limitations by extending grammar languages with the recomposition ability. Fundamental is the concept of rule inlining, allowing for the topological recomposition of edited subparts by collapsing a shape subtree into one single shape on which derivation can continue. This is completed with a versatile geometry tagging system, allowing authors to compile and transport context information at any level of detail and gain full control over the geometry independent of the structure of the shape tree. Through various examples, we demonstrate the power of Recomp in procedural layout and mass modeling, as well as its capabilities in facilitating context-sensitive design.