Help me please on a displacement!

[wardy_mk]

Well, I need the displacement to work independently from the image in the background .... I was under the impression that using a decal is the way to do it in Corona?

[TomG]

It's not the only way, but is one of the most intuitive - but if mapping causes problems there are other solutions. First I can think of is combining the regular displacement map with the "special displacement" in some mix node like the Mixture shader, and sending the result into the displacement slot of the material. You could use the Corona Layered material too, as there are now options in there in how to handle blending displacements from different layers. You then have to control the positioning of the displacement via UV mapping though, which is what the Decal makes easier (and makes it easy to apply "just displacement" without having to duplicate underlying materials twice).