How to bake normal map for discontinuous mesh I'm building models for an independent game and would like to use normal maps. I started by building the low detail meshes first, which are about 4000 tris each, give or take a thousand. I built the low detail meshes in pieces to save on polycount, so when I bake a normal map onto the low poly mesh I get all kinds of errors where the high poly mesh is being projected onto the overlapping faces, no matter what bias I use.

How can I bake normal maps for these meshes? If I have to redo these to get there, what should I look out for in the future? Should I have started with a continuous mesh with all the detail and then deconstructed it to make a low detail mesh?
Here is a workflow you could use:


Build the high poly mesh first. 
Add details as you like by adding separate meshes.
Build the low poly mesh over high poly mesh, using Shrinkwrap and Surface Snapping to help.
Separate your low poly meshes according to requirements (textures, extrusion etc).
Bake your maps.


This ensures correct normal and AO map bakes.