Normal maps on 3D models often break during export due to UV mapping errors, coordinate space mismatches, or incorrect export settings.
UV issues (like overlaps or stretching) distort how normal maps apply to the model’s surface. Coordinate space mismatches—e.g., using tangent space normals with a tool expecting object space—cause misaligned details. Incorrect settings (flipped normals, missing tangent data) can lead to artifacts or broken texture details.
To fix, check UVs for overlaps first, confirm the normal map’s coordinate space matches your export tool, and double-check settings (like “tangent space” options) before exporting again.