private static int AddFeat(
SkeletonFeatureFrame sff, SkeletonFeatureFrame.DirectionVectors feature,
double[] arr, int nextFreeIndex)
{
Vector3D v = sff.DirectionVector(feature);
arr[nextFreeIndex++] = v.X;
arr[nextFreeIndex++] = v.Y;
arr[nextFreeIndex++] = v.Z;
return nextFreeIndex;
}
