Flatten Mapping

[anonymous_user_e0f8f536]

Another question is , even for the objects which wasn’t unwrapped in , Unreal generates an additional UV map which is very similar to flattened maps of . What is this?

[Tim_Hobson]

@Querorz;220769

, thanks so much. Great to know having someone like you ready to help any time. I loved your little tutorials. Thank you.

Guys, isn’t there a plugin on unreal engine that works like “UVW Map” on 3ds ? Do i have to do unwrapping for everyyyyy single object on ? Even for the objects that doesn’t have any texture on it? For the ones that only have a white color material on it? There gotta be something to handle this operation easier way.

UVs cannot be edited via UE4. There is no plugin that has been created yet by anyone. UE4 can generate lightmaps though for your second UV channel. This will only repack the UV used for the texture though. So, it will not break any seams or flatten any things out that is using a projection UV method, which can lead to overlapping UV errors. It’s best to do the UVs in or whatever program that may be used to handle UV Editing.

The objects that need a lightmap really need need to be unwrapped. Flatmapping can work OK for smaller objects or ones that you may not need to worry about as much, but for your “Hero” objects that need the attention really need to be unwrapped in ways that get the best results.

Another question is , even for the objects which wasn’t unwrapped in , Unreal generates an additional UV map which is very similar to flattened maps of . What is this?

This will walk you through the process:
https://wiki.unrealengine/LightingTroubleshootingGuide#How_do_I_generate_lightmap_UVs_in_the_editor.3F

Essentially this is a RE-PACKING of your texture UV. It will take the UV shells that have been placed and repack them to have proper padding/spacing between other UV shells based on the minimum LM resolution you select. To reiterate again form earlier, if you have a lot of UV shells this will mean that the smaller the UV shell has to be in this space will be the less amount of resolution applied to that shell. A resolution of 32 or 64 would be really low for a large object broken up in pieces. Each one of those pieces would only be getting a minuscule portion of the LM texture space.

[anonymous_user_e0f8f536]

, thanks so much for all the detailed explanations and links. Here some new questions:

1- Is that “Generate Lighmap UVs” option necessary** only** if i didn’t unwrap a lightmap in ? Should i enable this option when i already unwrapped my own second channel UV in ?
2- When you use the modifier “UVW Map” in and select “Box” mode, it works for most of the objects. But why doesn’t it work in Unreal. Or does it ?

[Tim_Hobson]

@Querorz;220868

, thanks so much for all the detailed explanations and links. Here some new questions:

1- Is that “Generate Lighmap UVs” option necessary** only** if i didn’t unwrap a lightmap in ? Should i enable this option when i already unwrapped my own second channel UV in ?
2- When you use the modifier “UVW Map” in and select “Box” mode, it works for most of the objects. But why doesn’t it work in Unreal. Or does it ?

1. Yes if you want to have a lightmap with your static lighting. The answer is also, No. If you have a well laid out texture UV with no overlapping faces and enough padding you can use the Texture UV as well. This option was added in 4.5 to make it easier for those who didn’t know about 2nd UVs and didn’t understand what Lightmaps were when just starting out with the editor. The generated UVs has been there in some form since UE3/UDK. It was just refined a bit.

2. There are some caveats to using UVW Map. It can be used in to get your UV the way you like. This method will still produce overlapping UVs if you just apply a UV Map modifier. When you import just make sure the checkbox for “Generate Lightmap UVs” is set. This will take those projected faces that have been split apart and repack them. I tested this using a Cylinder, Box, and Sphere with good results. If you do not import with the option to generate lightmap UVs the mesh will have the “Invalid Lightmapping settings” material on the mesh.

[anonymous_user_e0f8f536]

, thanks , thanks , thanks. Completely understood. I won’t be disturbing you for a while now .

[Tim_Hobson]

@Querorz;221131

, thanks , thanks , thanks. Completely understood. I won’t be disturbing you for a while now .

No worries.

I enjoy helping and it helps me keep up with it all and learn new techniques as well.

Got this fortune cookie message today and it is absolutely true.

[anonymous_user_e0f8f536]

Guys, how to change UV resolution on ?

[JaxxTrend]

@Querorz;219516

Nawrot, thank you. Here is a part of UV’s of a huge building. Thousands of tiny islands as you said. On UV render , they are not overlapping. But i guess what you are saying is even though they look fine in render(which is 5000x5000 ) , there are probably less then 2-3 pixels between them in actual UV base. Because UV base(or whatever you call it) is only 2048-2048 pixels large and thousands of islands will have very little gaps in between? Is that right?

But, even if i unwrapped this building manually, there would be very few pixels between UV’s anyways. Because unwrapping them myself, doesn’t change the number of polygons and they will still cover a huge area.

The building i am working on is inunwrappable . It will take months to do it manually. So, i need an automated system for unwrapping. Does such a thing even exist?

I have same problem. Overlapping wake up when use wrong export options. Setup your fbx exporter like show in doc.