How to move a kinect skeleton to another position
- by Ewerton
I am working on a extension method to move one skeleton to a desired position in the kinect field os view.
My code receives a skeleton to be moved and the destiny position, i calculate the distance between the received skeleton hip center and the destiny position to find how much to move, then a iterate in the joint applying this factor. My code, actualy looks like this.
public static Skeleton MoveTo(this Skeleton skToBeMoved, Vector4 destiny)
{
Joint newJoint = new Joint();
///Based on the HipCenter (i dont know if it is reliable, seems it is.)
float howMuchMoveToX = Math.Abs(skToBeMoved.Joints[JointType.HipCenter].Position.X - destiny.X);
float howMuchMoveToY = Math.Abs(skToBeMoved.Joints[JointType.HipCenter].Position.Y - destiny.Y);
float howMuchMoveToZ = Math.Abs(skToBeMoved.Joints[JointType.HipCenter].Position.Z - destiny.Z);
float howMuchToMultiply = 1;
// Iterate in the 20 Joints
foreach (JointType item in Enum.GetValues(typeof(JointType)))
{
newJoint = skToBeMoved.Joints[item];
// This adjust, try to keeps the skToBeMoved in the desired position
if (newJoint.Position.X < 0)
howMuchToMultiply = 1; // if the point is in a negative position, carry it to a "more positive" position
else
howMuchToMultiply = -1; // if the point is in a positive position, carry it to a "more negative" position
// applying the new values to the joint
SkeletonPoint pos = new SkeletonPoint()
{
X = newJoint.Position.X + (howMuchMoveToX * howMuchToMultiply),
Y = newJoint.Position.Y, // * (float)whatToMultiplyY,
Z = newJoint.Position.Z, // * (float)whatToMultiplyZ
};
newJoint.Position = pos;
skToBeMoved.Joints[item] = newJoint;
//if (skToBeMoved.Joints[JointType.HipCenter].Position.X < 0)
//{
// if (item == JointType.HandLeft)
// {
// if (skToBeMoved.Joints[item].Position.X > 0)
// {
// }
// }
//}
}
return skToBeMoved;
}
Actualy, only X position is considered.
Now, THE PROBLEM:
If i stand in a negative position, and move my hand to a positive position, a have a strange behavior, look this image
To reproduce this behaviour you could use this code
using (SkeletonFrame frame = e.OpenSkeletonFrame())
{
if (frame == null)
return new Skeleton();
if (skeletons == null || skeletons.Length != frame.SkeletonArrayLength)
{
skeletons = new Skeleton[frame.SkeletonArrayLength];
}
frame.CopySkeletonDataTo(skeletons);
Skeleton skeletonToTest = skeletons.Where(s => s.TrackingState == SkeletonTrackingState.Tracked).FirstOrDefault();
Vector4 newPosition = new Vector4();
newPosition.X = -0.03412333f;
newPosition.Y = 0.0407479f;
newPosition.Z = 1.927342f;
newPosition.W = 0; // ignored
skeletonToTest.MoveTo(newPosition);
}
I know, this is simple math, but i cant figure it out why this is happen.
Any help will be apreciated.
