RealityKit–使对象始终位于屏幕前面

Question

我使用以下代码将对象保持在屏幕前，并用相机移动它。在didUpdate frame: ARFrame代理上，我调用getCameraPosition((。一切都很完美，现在我需要一个有效的解决方案来缩短处理时间。在目前的解决方案中，我觉得手机有时会挂断。如果存在PlaneInfinite&estimatedPlane不可用？这是我所做的视频链接。

extension ARView {

func getCameraPosition(from: CGPoint? = nil) -> Position {

let from = from ?? self.center
var result: ARRaycastResult?
if let raycast = self.raycast(from: from,
allowing: .existingPlaneInfinite,
alignment: .horizontal).last {
result = raycast
} else if let raycast = self.raycast(from: from,
allowing: .estimatedPlane,
alignment: .horizontal).last {
result = raycast
}
return result?.worldTransform.getPosition() ?? .zero

}
}
func session(_ session: ARSession, didUpdate frame: ARFrame) {

if self.viewModel.isFirstHorizontalPlanDetected {
DispatchQueue.main.async {
self.object.position =  self.arView.currentPositionOfCamera()
}
}           
}

Answer 1

这种情况下的最佳解决方案是使用trackedRaycast方法：

let query: ARRaycastQuery = .init(origin: SIMD3<Float>(),
direction: SIMD3<Float>(),
allowing: .estimatedPlane,
alignment: .horizontal)
let repeated = arView.session.trackedRaycast(query) { results in

guard let result: ARRaycastResult = results.first
else { return }

let anchor = AnchorEntity(world: result.worldTransform)
anchor.addChild(model)
arView.scene.anchors.append(anchor)
}

repeated?.stopTracking()

此外，您必须实现ray(through:)实例方法：

@MainActor func ray(through screenPoint: CGPoint) -> (origin: SIMD3<Float>, 
direction: SIMD3<Float>)?