[Insight-users] itkKdTree and bucket size?

[motes motes]

Where do I find some documentation/theory describing how to choose the
bucket size for the itkKdeTree? If I set it to the default which is 16
not all points are returned even if I specify a radius covering the
whole hypersphere (for 3D). But if I increase the bucketSize to eg.
100 I get all points within the radius.