How to create lightmaps for several objects attached using 3ds max uv map modifier

Hello everyone,

I am researching UE4 for my firm to use as a archviz tool. I have previous experience in UE3 but its been a while. (I am a game art grad who ended up in archviz.) I know that you have to create light maps for meshes but I’m curious about a specific. First let me explain my workflow. I work in 3DS Max to create scenes and when possible I just use the uv map modifier from max which uses a simple box or planar map method to create uvs for an object. Its useful for chairs or floors or something that doesn’t need to be unwrapped manually, but the uv’s are pretty ugly sometimes. So I have a scene that I rendered in VRAY originally but I’m trying to export the scene to UE4. That being said I exported in groups. For example, I exported all the furniture together as one fbx file, all the lights as one file etc. They all have a uv map but when exported together the uvs are obviously on top of one another and just crazy. Do I need to export each object seperately and unwrap the uvs for all objects to create the lightmaps correctly? Even ones that I want to use a basic material on? (laminate or alluminum) Obviously when I build the lighting I have overlapping lightmap uvs. This is probably a silly question so sorry guys! I’ll post images of my scene.

I have practically no experience with 3d max, apart from watching few tuts, but I think what you are looking for is UVW unwrap modifier-> change channel to 2->select all faces-> open editor->flatten mapping. There should be also a feature to automatically pack UVs.
However, take into considerations that UVs, produced that way, will be always be worse than proper unwrap for lightmapping.

Thanks for your quick response! I think I just need to be aware of UE4 workflow while building my scenes next time. It seems that the only way to get proper lightmaps is to unwrap things individually and make sure there aren’t any overlapping uv’s for the lightmap. Thanks again!

just to add to that, also make sure that uv’s are not mirrored for lightmaps.

Thanks Luos! Will do. I understand that you can mirror uv’s for diffuse purposes but there needs to be a unique uv map without mirrored uv’s for the lightmap purpose. Thanks for all your guys help.