Using a unique Physical Material for parts of landscape without a unique layer?

I’ve got a landscape with several Landscape Layers, each with a Physical Material set for footstep sounds. This works great in 4.24 currently.

In the LS material, I’m adding puddles on top of a specific Landscape Layer using a mask. This “puddle layer” does not have its own Landscape Layer or Layer Sample, it is simply blended into the final material.

Problem is, the layer is gravel underneath the puddles, and footstep traces return that layer, as you would expect.

Two ideas…

  • Is there any method to **automatically **identify the mask I am using for puddles, and use a different Physical Material in those cases?
  • Is there a way to populate a Layer Sample (Layer Info) from within the master material? For example, after the puddle mask is generated, copy it to a ‘Puddles’ Layer Sample which would be empty by default

The only other way I can think of is to manually export the final puddle mask for the entire landscape and copy it back into an invisible ‘Puddles’ Layer, with its own Phys Mat. But that will take a lot of extra work and is not so elegant.