To fix sharp (overly angular or jagged) polygons in 3D models, use smoothing modifiers or adjust vertex normals to blend harsh edges.
Smoothing tools (e.g., Blender’s Subdivision Surface, 3ds Max’s Turbosmooth) add small subdivisions to round edges. Normal editing changes how light reflects off faces, reducing harshness. For low-poly models, weighted normals help retain details while smoothing; for high-poly, check for duplicate vertices (a common sharpness cause).
Beginners can start with a basic one-click smoothing modifier—most software has this—and tweak subdivisions to balance smoothness and performance.