Algorithmic Design with Rhino and Grasshopper: From the Parametric Model to the BIM Model in Archicad

This recording captures a technical seminar from SIMBIM's virtual room devoted to algorithmic design, presented together with McNeel Europe. The session is led by Joana Alsasua, joined by David León, of McNeel Europe, who takes the Rhino and Grasshopper part. The approach is introductory: it is not a step-by-step tutorial but an explanation of what designing through algorithms means and of how that work then reaches the Archicad BIM model. David León places Rhino as a modeller based on NURBS surfaces, used in design, analysis, digital fabrication, prototyping and visualisation, and shows projects in which geometric complexity was resolved with Grasshopper definitions. He explains Grasshopper through the analogy of the cup of coffee: ingredients go in, a process combines them and the result comes out at the other end. He runs through the ecosystem of add-ons — physical simulation, structural optimisation, environmental analysis, landscape design — and what Rhino 6 and the version then in development brought: Quad Mesher, SubD modelling, rendering with Cycles, PBR materials, Rhino.Inside and Rhino.Compute. He then builds a definition from scratch. He draws the perimeter of a plot, turns it into a surface with Boundary Surface, subdivides its domain into four parcels, scales each of them from its own centre, sorts the points with Sort Along Curve to close a central courtyard, extrudes the four volumes with independent sliders, subtracts the courtyard with Solid Difference and deforms the whole with the Taper component. From the final volume he extracts a series of contours that will become the slabs. Joana Alsasua takes that same definition and shows the two-way connection with Archicad. From the Archicad tab inside Grasshopper she connects the geometry to a slab component, enables the connection in Archicad's interoperability section and the model appears built; moving a slider, the change is reflected in the project. The connection does not carry geometry alone: composites, layers, classification and properties are assigned from the components themselves. The second workflow runs the other way. Starting from a sports stadium modelled in Archicad, a shell is taken as the reference for generating beams and columns in Grasshopper, and when the façade is curved the structure adapts in cascade. It closes with a solar study using Ladybug on a curtain wall and a roof, the result of which leads to adding louvres with parameterised complex profiles.