Engraver

Engraver is an Blender addon with set of few tools designed to help carving decals in 3d models. This addon was designed to support modeling with custom normals workflow.

Engraver_v**.py - Addon for Blender 2.7*

Engraver_(2_8)_v**.py - Addon for Blender 2.8

How to use it:

Simply select your decal geometry, then select your surface geometry on which you want to place it, use ALT+Q shortcut and chose from available tools: 

Tools description:

Engrave - Merges predefined geometry of your decal onto selected surface geometry.

Engrave flat (Experimental) - This tool is still under development. It allows to define simple convex or concave decal from flat geometry. Works similar way as Engrave tool but instead of predefined decal geometry you can use flat geometry. After running the tool you can modify it's bevel by moving mouse and accept it by clicking LMB. After applying bevel width you're able to define depth of decal the same way as with bevel: mouse movement+LMP for apply.

Cut - Cut a crevice according to border edges of your flat decal geomtery.

Booleans - Simple boolean tools which maintains custom normal information of your meshes.

Mirror - Mirror model with custom normals.