I have been trying to use a texture to control hair density on my mesh and for the life of me cannot get hair dynamics to work with it. Couldn’t find a reference to this anywhere. Do hair dynamics not like texture maps? Dynamics work fine when simply using Vertex groups to control density. Have tested in on a simple scene with a plane as well… no dynamics.
I have not tested anything, but I suggest you trying out the blender gooseberry branch, because it has a much more advanced hair/particle system. If it works in blender, it will work in the gooseberry branch.
You can find the latest release here: https://builder.blender.org/download/