UV maps for 3D models have seams because 3D surfaces can’t be flattened into 2D without splitting—shapes like spheres or cylinders need cuts to unfold evenly without texture distortion.
- **Why seams are necessary**: Seams mark where the model is "unfolded" into a 2D UV layout. This prevents textures from stretching or warping, which is key for realistic renders. - **Fixing noticeable seams**: Hide seams on less visible edges (e.g., under clothing or behind objects) or use texture tools to blend edges for a smoother finish.