我尝试从 ARSession 的 currentFrame.camera 属性获取相机变换。
为什么我总是将 sceneView.session.currentFrame? 获取为 nil？
最佳答案
我刚刚进行了快速测试，发现 session.currentFrame 在前几次通过渲染循环时为 nil。延迟各不相同，可能是两个或十几个。但最终 currentFrame 出现了。
class ViewController: UIViewController, ARSCNViewDelegate, ARSessionDelegate, SCNSceneRendererDelegate {
override func viewWillAppear(_ animated: Bool) {
super.viewWillAppear(animated)
// Create a session configuration
let configuration = ARWorldTrackingSessionConfiguration()
configuration.worldAlignment = .gravityAndHeading
configuration.planeDetection = .horizontal
sceneView.session.delegate = self
// Run the view's session
sceneView.session.run(configuration)
print(#function, sceneView.session.currentFrame)
}
// MARK: - SCNSceneRendererDelegate
func renderer(_ renderer: SCNSceneRenderer, didRenderScene scene: SCNScene, atTime time: TimeInterval) {
print(#function, sceneView.session.currentFrame)
}
// MARK: - ARSessionDelegate
func session(_ session: ARSession, didUpdate frame: ARFrame) {
print(#function, sceneView.session.currentFrame)
}
给我们
renderer(_:didRenderScene:atTime:) nil
...
session(_:didUpdate:) Optional(<ARFrame: 0x1c42cff10 timestamp=6334.963644 capturedImage=0x1c0124d80 camera=0x1c41262c0 lightEstimate=0x1c4238640 | no anchors, 0 features>)
...
renderer(_:didRenderScene:atTime:) Optional(<ARFrame: 0x1c02c9c30 timestamp=6334.996948 capturedImage=0x1c0124b00 camera=0x1c0124920 lightEstimate=0x1c02251a0 | no anchors, 0 features>)
关于ios - ARKit session 的 currentFrame 始终为 nil，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/44902754/