I would like to integrate a function into my iOS app, that allows the user to use his or her device as a virtual camera, meaning they hit record, then the motion of the iPhone or iPad is captured and then when done, saved as an fbx or similar file format virtual camera movement. Is there a more of less easy way to do this? thanks in advance!
Hello chaert-s,
You can do this by serializing the transform data of the ARCamera every frame and writing it to disk (along with the time stamp of the frame).
You could also accomplish something like this using Model I/O (though I don't believe it will export to fbx, other common formats are supported though):
1. Create an MDLTransform object. 2. In the ARSession update method, set the translation and orientation of the transform based on the elapsed time:
func session(_ session: ARSession, didUpdate frame: ARFrame) {
if firstUpdateTime == nil {
firstUpdateTime = frame.timestamp
}
let transform = frame.camera.transform
let rotation = frame.camera.eulerAngles
let position = transform.columns.3
let elapsedTime = frame.timestamp - firstUpdateTime!
// cameraTransform is an `MDLTransform`
cameraTransform.setTranslation(position[SIMD3(0,1,2)], forTime: elapsedTime)
cameraTransform.setRotation(rotation, forTime: elapsedTime)
}
// A box to visually represent the camera as it animates through the scene.
let object = MDLMesh(boxWithExtent: .init(0.1, 0.1, 0.1), segments: .init(10, 10, 10), inwardNormals: false, geometryType: .triangles, allocator: nil)
object.name = "Camera Transform"
object.transform = cameraTransform
let asset = MDLAsset()
asset.add(object)
try! asset.export(to: url)
