UDK Lighting help (preview looks crazy differnt from built lighting)

[Ubersock]

Hi everyone I have a question about UDK lighting, I am getting some strange results when baking lighting and I was wondering if anyone can help me and tell me what i am doing wrong, I am fairly new to UDK and extremely new to the lighting process in UDK.

Here is my scene with me just placing lights and changing there colors and radius

http://ubersock.com/rundown_building/rd_pre_lit.jpg

Here is the same scene after building lighting

http://ubersock.com/rundown_building/rd_built_lit.jpg

and here is the just lighting button in UDK

http://ubersock.com/rundown_building/rd_just_built_lit.jpg

[Ben Apuna]

I can't really say for sure but a very common mistake is not setting up proper light map UVs on you meshes, or not directing the light maps to build with the right UV channel.

Are you using Lightmass to build your lighting?

Here are a few posts I've made on this subject from the UDK master thread, sorry they're not specific to you but they might help point you in the right direction:

http://boards.polycount.net/showpost.php?p=1098043&postcount=635

http://boards.polycount.net/showpost.php?p=1099353&postcount=651

http://boards.polycount.net/showpost.php?p=1099952&postcount=655

EDIT:

Oops! I forgot to mention that before you build the lighting Unreal uses dynamic lighting by default, that's why you get a big difference between built and not built lighting.

[Ubersock]

I can't really say for sure but a very common mistake is not setting up proper light map UVs on you meshes, or not directing the light maps to build with the right UV channel.

Are you using Lightmass to build your lighting?

Here are a few posts I've made on this subject from the UDK master thread, sorry they're not specific to you but they might help point you in the right direction:

http://boards.polycount.net/showpost.php?p=1098043&postcount=635

http://boards.polycount.net/showpost.php?p=1099353&postcount=651

http://boards.polycount.net/showpost.php?p=1099952&postcount=655


great suggestions i never uv mapped my other channel in max, which buy default i think is 3 in max so should be 2 in udk ( right ) so im assuming it is all tiled like my textures . checking out your links now

[Ben Apuna]

Yup, Max UV channel ID = UDK Light Map Coordinate Index -1.

Typically in UDK your diffuse/normal/spec/etc. maps will be mapped to coordinate index 0 (Max UV channel 1) and your light maps will be baked using coordinate index 1 (Max UV channel 2).

You can use whatever coordinate index/UV channels you want for anything you want but by default UDK will set your Light Map Coordinate Index to 1.