Super Noticeable Seam after Baked lighting please help.

Trevion3D

Hey guys! for the last 3 hours i've been going slightly insane. so far i've been pulling my hair out and only have a bout 1/4 of my hair left on my head.

I've been making this train and everything is perfect its just that when i bake lighting i get this huge seam where i mirrored the geometry please help me fix this! i want to keep at least some of my hair. thank you in advance, who ever can help me.

Zipfinator

Looks like a lighting problem. Did you mirror the geometry in Unreal? Not sure how to fix it if so. If you mirrored it in Max then you just need to weld the vertices together after mirroring.

Trevion3D

I did weld them, but i cant figure out what the Dealio is. seam only apears after baking lighting. i made a light channel for it and everything. cant figure out whats the deal

noname

Do you have a seam in your lightmap uvs there? Try stiching them together. I had a similar problem and that fixed it for me.

Other things I can think of, that could be causing this, are overlapping uvs or bleeding caused by a small lightmap resolution whitout enought padding for the uv islands.

Trevion3D

hmm well, i stitched the light maps and it definatly has enough room and there are no overlapping uv in the Light channel. I think its a geometry issue, but i dont know why everything is fine if its an interpactor, as soon as its lit, it goes to shit :'''(

Ben Apuna

From another post, hopefully this helps:

Ben Apuna wrote: »

Looks like the mirrored normal map in UDK issue. Before you get really involved trying to fix this keep in mind it can't be solved 100%, just reduced.

Here's a copy/paste from a PM with another Polycounter:

You'll need to make sure that the UV seam runs vertically in relation to the UV window. In other words mirror the UVs like turning the pages of a book rather than the pages of a calender (I forgot who came up with that analogy, but it's a good one.).

The geometry itself should be flat where the UV seam is located as well.



Another thing that can have a big impact on mirror seams with baked lighting is lightmap UVs. It's best to have as few seams as possible on the lightmap UVs in order to keep the lighting smooth and continuous. Of course if you want hard edged lighting like around a 90° corner for instance then you need to split the lightmap UVs.

Lightmap UVs in Unreal also need at least 2 pixels of padding around each shell, so 4 pixels total between two shells to avoid light bleeding from one shell to another.

You can also try to turn the Indirect Normal Influence Boost to 0 rather than the default of 0.3(?), this seemed to help reduce the specular seam that happens with mirrored normal maps in older versions of UDK (I haven't switched to a newer one for a while...). The setting can be found under:

View -> World Properties -> Lightmass -> Lightmass Settings -> Indirect Normal Influence Boost

And lastly even with all of that work the seam will only be minimized, not removed 100%

Good luck.

EDIT:

Hmm... looks like I forgot to mention you need to mirror your triangulation as well, even though the triangulation on the base of my barrel there isn't mirrored properly as it should have been :poly136:

EDIT2:

Just a thought but now with FBX explicit vertex normals import possible with static meshes, there might be some vertex normal editing tricks that might help solve this issue as well. Definitely worth some experimentation...

Trevion3D

Thanks Guys For your support. I will play with these possibilities. It just blows my mind that UDK lighting looks better (sometimes) in preview mode. then you wait for a bake and produces this result. If anyone else has any advice Please don't hesitate to post!

tristamus

It could possibly be that, if those are 2 meshes meeting at the point where that seam is, you need to point the vertex normals straight up 90 degrees for both the mesh pieces, where they meet. That is if I'm understanding this situation correctly...

I know that issues like this have been solved using the FBX file formats "Use Explicit Normals" option when importing into UDK.

Arac

This might also help:

http://udn.epicgames.com/Three/LightMapUnwrapping.html

In UDK you can only mirror your UV's along the X axis.