What is an overhang in a 3D model?

An overhang in a 3D model refers to a section that extends outward from the last fully supported layer beneath it. This terminology is crucial in 3D printing, particularly in processes like Fused Deposition Modelling (FDM), where materials are deposited layer by layer. When part of a model overhangs significantly without sufficient support below, it can lead to print failures due to the material drooping or collapsing during the printing process.

Understanding overhangs is essential for effective model design, as they require careful consideration for support structures or accommodating printing techniques to ensure successful fabrication. The presence of overhangs often dictates the need for additional supports or a redesign of the model to reduce unsupported areas. The other options address features or structures that either enhance stability or add aesthetic value, but they do not accurately define what constitutes an overhang in the context of 3D printing.