# Grasshopper Algorithmic Modelling: Parametric Design for Product Platform Customisation
## 4 Case Studies
### Case Study 2: Outdoor Furniture Platform  
The second case corresponds to the design of a family of outdoor furniture. It is developed as a scale-based platform whose main function is to provide seating with different characteristics. The particularity of this platform lies in the diversity of positions of use, which gives rise to variations in shapes. On this platform, algorithmic modelling plays a key role, allowing adjustments to be made to the dimensions of the product.  
Figure 3: Grasshopper algorithm of Case Study 1.  
Through the modification of the roundings, dimensions, and repetition of serial planes, products are created that offer different body support configurations. Backrests, armrests, and leg supports can be customised, generating a diversified product range that forms the family within the platform. In addition, the diversity of design solutions, as well as materials and colours, can be adapted to different contexts of use [78].  
During the conceptual design phase, a series of sketches were created to explore the geometric possibilities of the seating profiles. To address the transitions between circular elements, certain points and rounding were modified, along with repetitions of serial planes. These transitions were mathematically controlled using smooth interpolation curves, ensuring continuous and aesthetically pleasing connections between the elements. Therefore, the algorithm can generate all products that form part of the platform.  
The GH design process involved rigorous study and experimentation to develop a detailed algorithm (Figure 4), divided into four functional blocks. First, the base points and associated curves, blue block, were created and linked with the technically generated arcs, orange block. Subsequently, additional points were added for details such as armrests and yellow blocks, and all curves were joined together to form complete seat profiles. By repetitions, the serial planes were created, green block. The curves were generated proportionally using an initial radius based on the golden ratio. Structural points were defined on an XZ plane with measurements in centimetres. Tangent arcs connected the curves and were adjusted using shatter blocks to eliminate excess. The profile was obtained by joining the curves and duplicating them to add thickness, creating the surfaces that make up the seat. Finally, the profiles were extruded in repeated serial planes in the Y direction and assembled into a single 'Brep'. This three-dimensional model was exported to RH and prepared for final presentation. It demonstrated how a single algorithm can generate a functional and aesthetic design in the parametric environment of GH. The full script of the case study can be consulted (see Data Availability Statement).  
With respect to the selection of variables in Table 1 (see Section 2), Group 1 includes only those parameters that have a direct impact on product customisation: dimensions, proportions, colour, rounding, pattern, and materials. As in the previous case, all Group 2 parameters were included for evaluation.