I cannot figure out how to use interpolated children with hair particle systems correctly. Simple children behave more or less as expected, appearing near the parents, spread distance being determined by the radius parameter. But when I switch to interpolated, the chldren are distributed randomly all over the mesh, the locations seemingly completely uncorrelated with the ones of the parents. The manual says:
Children are emitted between the Parent particles on the faces of a mesh. They interpolate between adjacent parents.
Whatever that exactly means, to me it doesn't sound like what happens in my example, below. What I am doing wrong?
This is the way the parents are placed:
So it looks with simple children:
And this way with interpolated ones: