Custom Normals don't work on Displacement Modifier

[littlebirdpal]

Hey there!

I would like to have a mesh displacement along custom normals but it does not seem to work the way it should.
My custom normals look like this:

But the rendered displacement looks like this:

So it’s still basically using the vertex normals.
Doesn’t work either when I activate the modifier for the render.
The texture I use is full of white dots on black background.

Why is this the case? Can someone give me some advice?
Thank you!

[etn249]

In the subdivision modifier, go into the advanced tab and check “use custom normals”, or else the subdivision will override them.