I’m coming here as I’ve tried several things over the course of the day including using Booleans / modeling this in. Trying a decal. Only using bump which looks naff.
Literally, all I’m trying to do is deboss this bird logo into the cylinder
linear displacement normally requires a + and - value where 50% grey = 0%.
So in your case 0% displacement is grey (use a soild colour layer) and the dove bitmap is -X (use the image on top multiplied) with and equivalent +X value
Nope, you must be doing something incorrectly since it works on my side.
@davetwo is right, the correct workflow is to use a different map than for the bump and use a 50% gray color where the geometry should not move. But Corona allow you to set min/max level ( some render engine only have one value = the total height of the displacement ) and you can take advantage of this. So -3/0 with a black and white map or -3/+3 with a gray map is really just the same thing.