This paper presents a comparative study of two interaction paradigms for producing photorealistic, real‑time variations of parametric forms: conventional keyboard and mouse input or voice commands. The practical work implements a prototype workflow linking Grasshopper and Unreal Engine via a .CSV data bridge. Evaluation metrics include refresh latency, control accuracy, and user usability, tested on instanced façade panel scenarios. The study aims to determine which interface delivers faster, more precise, and more accessible presentation of parametric variations in architectural practice.