Why is Baked Lighting is "Burned Out" on some surfaces? (Unity 5.4 & 5.5)

Unity Engine
1

Hello, I’ve been having problems with baked lighting and global illumination.
Some entire surfaces of the room in my scene there are completely darkened after baking lighting.

Some info:

  • Happens in Unity 5.4.3 and 5.5.1
  • Mesh is from Sketchup > FBX > Unity
  • Generating lightmap UVs in Unity or creating my own doesn’t solve the problem
  • Generating tangents and normals or not in Unity doens’t solve the problem
  • All wall surfaces are supposed to be white
  • Opening the lightmap directly shows that all the lighting is baked without problems with no “burning”
  • “Burning” of surfaces only shows inside of Unity.
  • I’ve tried changing ambient light to white/grey but the burn is still blue.

  • All wall surfaces are supposed to be white, but it is visible here that the back wall and bed are somewhat “burned” out.


Opening the lightmap directly shows that all the lighting is baked without problems with no “burning”

Does anyone know of the solution for this? Thanks!

UPDATE:
I have discovered more details. The problem stems from using directional lights in the scene. If the light doesn’t cast on a wall, that wall won’t have the “burn out” effect. See the following 3 images


directional light on + shadows.

directional light on + shadows, rotated another direction
directional light off. no more burn effect

2

Maybe baked view can help you identify the problem.

In case you develop for mobile platform, The bug can be easily verify by switching to standalone.

3

Thanks for the suggestion. I took a look at the GI views and they all look very normal, so its not that problem

4

I have discovered more details. The problem stems from using directional lights in the scene. If the light doesn’t cast on a wall, that wall won’t have the “burn out” effect. See the last 3 updated images

5

Try turn off Ambient Occlusion. If Ambient Occlusion doesn’t cause it, I don’t have anymore idea.