To import a 3D model with a normal map, use a compatible tool (e.g., Blender, Unity), load the model file (FBX/OBJ), and link the normal map in the material settings.
Normal maps add surface detail (like wrinkles or grooves) without extra polygons—keeping models realistic while saving file size. For example: In Blender, add the normal map to the Shader Editor’s Normal input; in Unity, assign it to the material’s “Normal Map” slot.
If the normal map looks off, check if your software uses “Tangent Space” (standard for most models) or adjust the texture’s green channel (some tools flip it for compatibility).