Your blend shapes 3D model is ugly usually because of uneven shape transitions, low polygon density, or mismatched topology between the base and target shapes.
Uneven transitions make movements (like facial expressions) jittery, low polygons cause blockiness, and mismatched vertices break smooth blending—common issues in rigs or animated objects.
Troubleshoot by matching vertex counts (most tools have "transfer topology" features) or testing small, incremental shape adjustments to avoid harsh deformations.