Hi everyone,
Sometimes Blender’s built-in armature deform with automatic weights throws: “bone heat weighting: failed to find solution for one or more bones”, then give up.
It’s annoying, so I released an open source add-on to generate similar results, but it never fails, you may think it a stable version of bone heat weighting.
I have put it on Github: Surface Heat Diffuse Skinning - Blender Add-on v1.0
Cheers!