Why is high poly 3D model distorted when optimize?

High poly 3D models often distort during optimization because polygon reduction tools may remove or simplify critical shape details—especially in complex areas like curves or fine features. Optimization balances lower polygon count with retaining appearance, but aggressive settings or misidentifying key vertices/edges can warp surfaces (e.g., smoothing sharp creases into blurriness or creating uneven vertex spacing that breaks the original shape). To fix distortion, adjust the tool’s edge preservation or detail threshold, or manually touch up problem areas to keep key features without extra polygons.