Length of Object at Location?

[WAS]

Is it possible to use functions to get the length in Y of an object at it's location in the population? To do altitude-like restrictions but just based on the objects normal length or something?

Take my dying or fall variant of the Austrian Pine from Xfrog.

I want to make a true dying variant where there is more dead foliage at the bottom indicating some sort of blite or root pathogen.

[Dune]

It should be possible to use a (not final) distribution/surface  shader and displace/warp that as the terrain and use as mask.

[WAS]

Thanks I'll give that a try.