Question

现在，我使用ARKit 2.0创建了一个应用程序，但是我不知道如何将参考图像放入核心数据中。因为每次我启动该应用程序时，它都会再次创建参考图像。

var aRIngredients = Set<ARReferenceImage>()
let arImage = ARReferenceImage(((image?.cgImage))!, orientation: CGImagePropertyOrientation.up, physicalWidth: 0.5)

self.ARIngredients.insert(arImage)

configuration.trackingImages = self.ARIngredients

Answer 1

假设我正确地解释了您的需求，您可以执行以下操作：

首先，我们将在Entity中创建一个CoreData，在本示例中将其称为ARCustomImage，并将有两个attributes：

imageData（BinaryData）-我们将在其中存储SnapshotImage的地方。
名称（String）-目标图像的唯一ID。

确保像这样设置imageData属性：

然后让我们说我们要将ARSCNView快照保存到CoreData。然后我们可以做这样的事情：

/// Saves The Data Needed To Store Our ARReferenceImage
@IBAction func saveReferenceImage(){

    //1. Take A SnapShot Of The ARSCNView
    let screenShot = self.augmentedRealityView.snapshot()

    //2. Save To CoreData
    if let arImageEntry = NSEntityDescription.entity(forEntityName: ENTITY_NAME, in: databaseContext),
        let newCustomARImage = NSManagedObject(entity: arImageEntry, insertInto: databaseContext) as? ARCustomImage{

        //a. Set The Target Name Of Our ARReferenceImage
        newCustomARImage.name = UUID().uuidString

        //b. Store Our Image To The Stack
        newCustomARImage.imageData = UIImagePNGRepresentation(screenShot)

        do {
            try databaseContext.save()

            //c. Load The Custom Images Again So We Can Start Our Configuration With Custom Images
            loadExistingReferenceImages()

        } catch {
            print("Error Saving \(UUID().uuidString) ")
        }

    }else{
        print("Error Generation \(UUID().uuidString) ")
    }
}

然后我们可以检查是否有保存的数据，然后将它们转换为Set的{{1}}，如下所示：

ARReferenceImage

我没有注释每个部分，而是注释了所有代码，因此它应该是完全可以自我解释的（这里是完整的），前提是您当然可以通过默认设置来设置CoreData：

/// Loads All Our ARReferenceImages From CoreData
func loadExistingReferenceImages(){

    var trackingImages = [ARReferenceImage]()

    //1. Generate A Fetch Request For Our Custom ARImages
    let request = NSFetchRequest<NSFetchRequestResult>(entityName: ENTITY_NAME)
    request.returnsObjectsAsFaults = false

    do {

        //2. Get Our Saved Data
        let savedData = try databaseContext.fetch(request) as! [ARCustomImage]

        //3. Loop Through Them & Create Our ARReferenceImage
        for customImage in savedData {

            //b. Get The Target Name & Image Back From Our Data & Convert To A CGImage
            if let targetName = customImage.name,
                let image = UIImage(data: customImage.imageData!),
                let arCGImage = image.cgImage {

                //c. Get The Width Of Our Image
                let widthInCM: CGFloat = CGFloat(arCGImage.width) / CGFloat(47)
                let widthInMetres: CGFloat = widthInCM * 0.01

                //d. Create An ARReferenceImage
                let arReferenceImage = ARReferenceImage(arCGImage,
                                                        orientation: cgImagePropertyOrientation(image.imageOrientation),
                                                        physicalWidth: widthInMetres)

                arReferenceImage.name = targetName

                //e. Add It To Our Tracking Images Array
                trackingImages.append(arReferenceImage)

                print("""
                    ARReferenceGenerated
                    Name = \(arReferenceImage.name!)
                    Width = \(arReferenceImage.physicalSize.width)
                    """)

            }
        }

    } catch { print ("Fatal Error Loading Data") }

    //4. Set Our ARSession Configuration Detection Images Using The Images From CoreData
    if !trackingImages.isEmpty{
        print("Loading An Existing Total Of \(trackingImages.count) ARReference Images")
        configuration.detectionImages = Set(trackingImages)
        augmentedRealitySession.run(configuration, options:  [.resetTracking, .removeExistingAnchors ])
    }else{
        //2. Run A Standard Session
        print("No ARReference Images Have Been Saved To CoreData")
        augmentedRealitySession.run(configuration, options:  [.resetTracking, .removeExistingAnchors])
    }

}

请注意，这只是一个非常粗糙的工作示例，并未以任何形状或形式进行优化。

话虽如此，它肯定会为您指明正确的方向...

如何将ARReferenceImage放入核心数据中？

1 个答案: