And this is the position of the text mesh object on the curved surface (before applying boolean modifier).
The curved modifier has been applied at this point to make the curvature of the mesh permanent.
As you can see, it is halfway inside the curved surface of the hollow cylinder.
Text object is 1.5mm thick, so it is 0.75mm inside the surface.
Since the boolean modifier is not working for the curved surface, what alternative do I have?
Booleans are not a sure fire process. Unlike CAD which uses a curve system and can generate topology as needed that will work virtually every time as there is little to no concern over whether or not you can edit individual vertices, using booleans in 3-D means that it has to compute how to reroute geometry, frequently, very poorly. Try tinkering with exact verses fast boolean settings. The other suggestion I have is, reduce the topology of the tool object. Dense topology on your tool object means that vertices located further away on the target object have to work harder to figure out which specific vertices they will attempt to attach themselves to and sometimes, I don’t know if it’s just getting confused, or just giving up, but the result is the same either way. Give those two things a shot and let us know if it is still having problems. One last thing to consider is to be careful that vertices do not exactly line up with edges on the target object. I’m not entirely sure why but it struggles a little bit with that also
Some times recalculating the normals works which cause the boolean>exact to cause this issue… go in edit mode of the text and select everything and press shift+N and on the bottom left menu check INSIDE
Or you can use the ‘fast’ one and also apply the scale for both objects. See if it helps!
I’m referring to your last pic - you have ‘un-applied’ scale and rotation - apply it and re try, make sure the other object(boolean mod) does not have un-applied scale or rotations.
As for the answer about ‘engraving’ on a curve - when possible start with a flat surface and use the ‘Simple Deform’ modifier (set to Bend) on both objects - there ‘origin point’ must be the same, add the ‘Boolean’ modifier to the flat surface using your ‘text’ object as the difference, apply it or not and there you have it.
Depending on the context, you can also use displacement maps (either with micropolygon displacement or with the modifier), or use height maps instead of trying to do it with booleans. I find this approach much more practical in most cases.
Only if it overlaps itself, reduce the bevel depth/amount and maybe the resolution - use wire overlay mode so you can see whats going on. Internal / overlapping geometry won’t be good for boolean mod.
