Blotchy Squares in lightmaps (Progressive lightmapper)

I keep getting these weird patches of squares in my lightmaps. I’m using the Progressive lightmapper on Unity 2017.3.0f3. Here were my settings (I’ve tried different variations) and results:

I’ve tried the following:

  • Creating new lightmap parameters and setting backface tolerance to 0
  • Increasing lightmap resolution and size
  • Using a test scene consisting of primitive cubes, ended up with the same blotchy result
  • Using baked directional lighting

Lighting has been a major source of pain recently and I’d appreciate any help I can get.

Turns out the noise is generated from compressed lightmaps. As soon as I unchecked the compress lightmaps setting in the lighting window all of my problems faded away.