True displacement mid level value

Question

I'm trying to use the Experimental True Displacement feature, but it seems that a grey value of .5 is not the default mid level?

I tried using a gradient map and also generated a displacement map for a little indent on a wall, But my results are that the wall in it's entirety gets displaced and puffs up.

Am I missing something? Is there a setting somewhere where I can pick the desired midlevel? Or can somebody tell me what color value can be used for zero displacement?

Thank you!

Answer 1

Ok silly me,

It seems that the color black is used for zero displacement. So you have to use a math node on your height map to generate negative displacement with negative color values.