/// <summary>
/// Calculate the distance between a point in a space and a plane. This method is used
/// to calculate the distance between a camera in a space and a specified plane.
/// </summary>
/// <param name="planePose">ARPose of a plane.</param>
/// <param name="cameraPose">ARPose of a camera.</param>
/// <returns>Calculation results.</returns>
private static float CalculateDistanceToPlane(ARPose planePose, ARPose cameraPose)
{
// The dimension of the direction vector is 3.
float[] normals = new float[3];
// Obtain the unit coordinate vector of a normal vector of a plane.
planePose.GetTransformedAxis(1, 1.0f, normals, 0);
// Calculate the distance based on projection.
return((cameraPose.Tx() - planePose.Tx()) * normals[0] // 0:x
+ (cameraPose.Ty() - planePose.Ty()) * normals[1] // 1:y
+ (cameraPose.Tz() - planePose.Tz()) * normals[2]); // 2:z
}
private List <ARPlane> GetSortedPlanes(System.Collections.ICollection allPlanes, ARPose cameraPose)
{
// Planes must be sorted by the distance from the camera so that we can
// first draw the closer planes, and have them block the further planes.
Java.Util.ArrayList pairPlanes = new Java.Util.ArrayList();
foreach (Java.Lang.Object item in allPlanes)
{
ARPlane plane = item.JavaCast <ARPlane>();
if ((plane.Type == ARPlane.PlaneType.UnknownFacing) ||
plane.TrackingState != ARTrackableTrackingState.Tracking ||
plane.SubsumedBy != null)
{
continue;
}
// Store the normal vector of the current plane.
float[] planeNormalVector = new float[3];
ARPose planeCenterPose = plane.CenterPose;
planeCenterPose.GetTransformedAxis(1, 1.0f, planeNormalVector, 0);
// Calculate the distance from the camera to the plane. If the value is negative,
// it indicates that the camera is behind the plane (the normal vector distinguishes
// the front side from the back side).
float distanceBetweenPlaneAndCamera = (cameraPose.Tx() - planeCenterPose.Tx()) * planeNormalVector[0]
+ (cameraPose.Ty() - planeCenterPose.Ty()) * planeNormalVector[1]
+ (cameraPose.Tz() - planeCenterPose.Tz()) * planeNormalVector[2];
pairPlanes.Add(new Pair(plane, distanceBetweenPlaneAndCamera));
}
//Get Pair object from ArrayList
List <Pair> sortedList = new List <Pair>();
IIterator myit = pairPlanes.Iterator();
while (myit.HasNext)
{
sortedList.Add((Pair)(myit.Next()));
}
//Sort Pair objects by plane in list
sortedList.Sort(new PlanCompare());
//Obtain plane list.
List <ARPlane> listOfPlane = new List <ARPlane>();
foreach (Pair item in sortedList)
{
listOfPlane.Add((item.First).JavaCast <ARPlane>());
}
return(listOfPlane);
}