Problem with object loosing all light on it after build - coming in from Blender 2.76b >>>

I am doing this to the material for the cave.

This looks fine in the viewer BEFORE build.

After I do a build all light vanishes off object.
Looks like normal map shows and only indirect light.

Lightmap resolution min is set at 64.
Lightmap res is set at 128.
Mesh is coming in from Blender 2.76b with 2 UV channels.
I am in U4.10.2
(It did show an error that smoothing groups couldn’t be found. I did apply smoothing modifier on fbx export)

Can someone tell me what the problem might be here?
I have been importing meshes for 5 levels the same way and this is the first time I see this problem.
Thank you.

So here is material on another level. I am doing the exact same thing with it only
difference is I am not applying a smooth modifier to the mesh before I export it from Blender.
Here it works fine. So the problem must be the smooth modifier in Blender then ???

So my take on this is the smooth modifier in Blender messes with the light map inside
Unreal 4.

Here is the answer: https://www.youtube.com/watch?v=BecR71sb30k

So what I am doing now is using only the smooth faces option in Blender. I am not using the “add modifier” function where you can have both sharp edges and smooth ones (in different groups) on the same mesh. Just keep it simple I guess.
If I need sharp areas I would import a different mesh. This is working just fine :slight_smile:

All seems fine now. I discovered that breaking the cave mesh up into 2 separate meshes and UV mapping them on their own gives far better results. All my “light holes” disappeared. Not perfect but a lot better.

I did see that white flash at his foot. First time I see that. Not sure what that is. Maybe someone can chime in and comment.

Actually to answer myself here on the issue of the white flash at his foot, that is light leaking through the ceiling of the cave.
So looks like the light map here is still glitchy. I just played in the viewer again and I see more light hits on his feet and legs.