Add this function in a subclass to get a notification just before a model (.fbx, .mb file etc.) is imported.
This lets you control the import settings through code.
// Disable import of materials if the file contains // the @ sign marking it as an animation.
class DisableMaterialImport extends AssetPostprocessor { function OnPreprocessModel () { if (assetPath.Contains("@")) { var modelImporter : ModelImporter = assetImporter; modelImporter.importMaterials = false; } } }