Unity has provided Lightmap seam stitching for its Progressive Lightmapper. You may also check that if you need this.
This is a part time project just for fun. No heavy use in project yet. If you have any problem and are willing to provide scene example, I'll dig in when free.
Just a corner case: a cube with different lightmapped color on faces.
After optimizing seams, these connect faces get blurred.
Just for comparsion, optimized lightmap with Point sampling.
All the functions are provided in the
- To Andreas for his seamoptimizer. (I also like his work lightmapper a lot!)