sloping altitude measurement?

[Dune]

I can't figure something out, and it may be terribly simple. I have a height tif, raising an island. Now I need to have the upper 1m layer of the ground in a different color (topsoil). I can't use altitude constraints directly for obvious reasons (it would be a straight line). 

I've tried warping a distribution shader (not final of course) by the tif, tried all sorts of displacement to scalar, color adjust, warp, vector displacement of the tif combinations... everything. Nothing works.

So any ideas are welcome!

[schmeerlap]

it may be terribly simple.

I can only be of help if it is terribly terribly simple. You know how you add a thick layer of snow on the ground with a surface layer with displacement. Would that give you the topsoil layer you're after?

[Dune]

No, is the quick answer. There should be another way.

[Stormlord]

I'm not an expert, but could normal and flip lead you to a solution?
https://planetside.co.uk/wiki/index.php?title=Visualise_Normal

STORMLORD

[aknight0]

Maybe something with Get Altitude vs Get Altitude in Texture?  https://planetside.co.uk/wiki/index.php?title=Masking_with_Get_Nodes

[aknight0]

Or can you use the tif as a mask, and shrink it just a bit?  Here's a simple shape shader masked with a slightly smaller simple shape shader.

[Dune]

Thanks for thinking along, guys. But those options won't work. It's a cliffy island, so a reduced tiff won't be very precise.

Anyway, I found the solution. I thought I had it somewhere in the back of my brain, some part I didn't use for a while I did use this method before, many years ago, I vaguely remember. It is indeed very simple.