过滤 ARSCNView 快照： 如果您想为您的 ARSCNView 创建一个黑白屏幕截图，您可以执行类似的操作，它会在灰度中返回 UIImage，而 augmentedRealityView 指的是ARSCNView:
/// Converts A UIImage To A High Contrast GrayScaleImage
///
/// - Returns: UIImage
func highContrastBlackAndWhiteFilter() -> UIImage?
{
//1. Convert It To A CIIamge
guard let convertedImage = CIImage(image: self) else { return nil }
//2. Set The Filter Parameters
let filterParameters = [kCIInputBrightnessKey: 0.0,
kCIInputContrastKey: 1.1,
kCIInputSaturationKey: 0.0]
//3. Apply The Basic Filter To The Image
let imageToFilter = convertedImage.applyingFilter("CIColorControls", parameters: filterParameters)
//4. Set The Exposure
let exposure = [kCIInputEVKey: NSNumber(value: 0.7)]
//5. Process The Image With The Exposure Setting
let processedImage = imageToFilter.applyingFilter("CIExposureAdjust", parameters: exposure)
//6. Create A CG GrayScale Image
guard let grayScaleImage = CIContext().createCGImage(processedImage, from: processedImage.extent) else { return nil }
return UIImage(cgImage: grayScaleImage, scale: self.scale, orientation: self.imageOrientation)
}
因此使用它的一个例子可能是这样的：
override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
//1. Create A UIImageView Dynamically
let imageViewResult = UIImageView(frame: CGRect(x: 0, y: 0, width: self.view.bounds.width, height: self.view.bounds.height))
self.view.addSubview(imageViewResult)
//2. Create The Snapshot & Get The Black & White Image
guard let snapShotImage = self.augmentedRealityView.snapshot().highContrastBlackAndWhiteFilter() else { return }
imageViewResult.image = snapShotImage
//3. Remove The ImageView After A Delay Of 5 Seconds
DispatchQueue.main.asyncAfter(deadline: .now() + 5) {
imageViewResult.removeFromSuperview()
}
}
这将产生如下结果：
为了使您的代码可重用，您还可以创建一个 extension of `UIImage:
//------------------------
//MARK: UIImage Extensions
//------------------------
extension UIImage
{
/// Converts A UIImage To A High Contrast GrayScaleImage
///
/// - Returns: UIImage
func highContrastBlackAndWhiteFilter() -> UIImage?
{
//1. Convert It To A CIIamge
guard let convertedImage = CIImage(image: self) else { return nil }
//2. Set The Filter Parameters
let filterParameters = [kCIInputBrightnessKey: 0.0,
kCIInputContrastKey: 1.1,
kCIInputSaturationKey: 0.0]
//3. Apply The Basic Filter To The Image
let imageToFilter = convertedImage.applyingFilter("CIColorControls", parameters: filterParameters)
//4. Set The Exposure
let exposure = [kCIInputEVKey: NSNumber(value: 0.7)]
//5. Process The Image With The Exposure Setting
let processedImage = imageToFilter.applyingFilter("CIExposureAdjust", parameters: exposure)
//6. Create A CG GrayScale Image
guard let grayScaleImage = CIContext().createCGImage(processedImage, from: processedImage.extent) else { return nil }
return UIImage(cgImage: grayScaleImage, scale: self.scale, orientation: self.imageOrientation)
}
}
然后您可以像这样轻松使用它：
guard let snapShotImage = self.augmentedRealityView.snapshot().highContrastBlackAndWhiteFilter() else { return }
记住你应该把你的扩展放在你的class declaration上面，例如：
extension UIImage{
}
class ViewController: UIViewController, ARSCNViewDelegate {
}
因此，根据您问题中提供的代码，您将得到如下内容：
/// Creates A Black & White ScreenShot & Saves It To The Photo Album
@IBAction func changeTextColour(){
//1. Create A Snapshot
guard let snapShotImage = self.augmentedRealityView.snapshot().highContrastBlackAndWhiteFilter() else { return }
//2. Save It The Photos Album
UIImageWriteToSavedPhotosAlbum(snapShotImage, self, #selector(image(_:didFinishSavingWithError:contextInfo:)), nil)
}
///Calback To Check Whether The Image Has Been Saved
@objc func image(_ image: UIImage, didFinishSavingWithError error: Error?, contextInfo: UnsafeRawPointer) {
if let error = error {
print("Error Saving ARKit Scene \(error)")
} else {
print("ARKit Scene Successfully Saved")
}
}
黑白实时渲染：
使用diviaki 的这个绝妙答案，我还能够使用以下方法让整个相机画面以黑白方式呈现：
第一。像这样注册ARSessionDelegate：
augmentedRealitySession.delegate = self
第二。然后在以下委托回调中添加以下内容：
//-----------------------
//MARK: ARSessionDelegate
//-----------------------
extension ViewController: ARSessionDelegate{
func session(_ session: ARSession, didUpdate frame: ARFrame) {
/*
Full Credit To https://stackoverflow.com/questions/45919745/reliable-access-and-modify-captured-camera-frames-under-scenekit
*/
//1. Convert The Current Frame To Black & White
guard let currentBackgroundFrameImage = augmentedRealityView.session.currentFrame?.capturedImage,
let pixelBufferAddressOfPlane = CVPixelBufferGetBaseAddressOfPlane(currentBackgroundFrameImage, 1) else { return }
let x: size_t = CVPixelBufferGetWidthOfPlane(currentBackgroundFrameImage, 1)
let y: size_t = CVPixelBufferGetHeightOfPlane(currentBackgroundFrameImage, 1)
memset(pixelBufferAddressOfPlane, 128, Int(x * y) * 2)
}
}
这成功地呈现了黑白照片：
过滤黑白 SCNScene 的元素：
正如@Confused 所说，如果您决定希望cameraFeed 是彩色的，但AR Experience 的内容是黑白的，您可以使用过滤器直接对SCNNode 应用过滤器filters 属性很简单：
要应用于渲染内容的核心图像过滤器数组
节点。
例如，假设我们使用Sphere Geometry 动态创建3 个SCNNodes，我们可以像这样直接将CoreImageFilter 应用于这些：
/// Creates 3 Objects And Adds Them To The Scene (Rendering Them In GrayScale)
func createObjects(){
//1. Create An Array Of UIColors To Set As The Geometry Colours
let colours = [UIColor.red, UIColor.green, UIColor.yellow]
//2. Create An Array Of The X Positions Of The Nodes
let xPositions: [CGFloat] = [-0.3, 0, 0.3]
//3. Create The Nodes & Add Them To The Scene
for i in 0 ..< 3{
let sphereNode = SCNNode()
let sphereGeometry = SCNSphere(radius: 0.1)
sphereGeometry.firstMaterial?.diffuse.contents = colours[i]
sphereNode.geometry = sphereGeometry
sphereNode.position = SCNVector3( xPositions[i], 0, -1.5)
augmentedRealityView.scene.rootNode.addChildNode(sphereNode)
//a. Create A Black & White Filter
guard let blackAndWhiteFilter = CIFilter(name: "CIColorControls", withInputParameters: [kCIInputSaturationKey:0.0]) else { return }
blackAndWhiteFilter.name = "bw"
sphereNode.filters = [blackAndWhiteFilter]
sphereNode.setValue(CIFilter(), forKeyPath: "bw")
}
}
这将产生如下结果：
有关这些过滤器的完整列表，您可以参考以下内容：CoreImage Filter Reference
示例项目：这是一个完整的Example Project，您可以自己下载和探索。
希望对你有帮助...