您可以保存世界地图以供以后检索。我想保存几张世界地图,但我找不到关于每张地图占用多少数据的任何信息。
每一个占用多少数据,是什么决定了数据的大小?例如,如果我在厨房里,那是一回事,但如果我在海滩上,那又是另一回事,如果我在商场里,那又是另一回事。我不确定它们是否会被视为小型压缩照片或大型未压缩视频的大小。
// Because ARWorldMap conforms to NSSecureCoding, you serialize it using NSKeyedArchiver:
func writeWorldMap(_ worldMap: ARWorldMap, to url: URL) throws {
let data = try NSKeyedArchiver.archivedData(withRootObject: worldMap, requiringSecureCoding: true)
try data.write(to: url)
}
// To restore the world map the next time your app launches, use NSKeyedUnarchiver:
func loadWorldMap(from url: URL) throws -> ARWorldMap {
let mapData = try Data(contentsOf: url)
guard let worldMap = try NSKeyedUnarchiver.unarchivedObject(ofClass: ARWorldMap.self, from: mapData)
else { throw ARError(.invalidWorldMap) }
return worldMap
}