3D artists (professionals and novices alike) often take inspiration from sketches or photos to guide their designs. Yet, existing modeling systems are not tailored to fully make use of such input. Consequently, significant effort and expertise are needed when creating model prototypes or exploring design options. In this work, we introduce a system to support the exploratory modeling process by enabling the transformation of 2D image elements into geometric 3D objects. Our solution relies on a novel d2 distance function, supporting a region-based lofting process, and delivers easily-editable 3D geometric "spine-rib" representations. The user draws a spine, and the system generates and modifies a generalized cylinder around it, considering image edges. The proposed approach, driven by simple user-defined scribble definitions, can robustly handle various image sources, ranging from photos to hand-drawn content.