Hello everyone !
The short question is : “When it’s not for Lightmap, Does Unreal engine deals with Unwrapped UV textures ?”
Here’s the context to my question.
I’m from 3DsMax and Unity, and I’m just starting to adjust to UE4. Most of the time the community and the documentation explains pretty well everything I need to work, but this time, I must admit I’m pretty confused.
It seams everyone on unreal engine deals with textures with IDs or UVW Maps, and only use Unwrap for Lightning. Maybe my methods are a bit old (I have no Idea how to manage IDs in Materials), but It seams I can’t apply a texture on a FBX with UVW coordonates ? Or Am I completely confused ?
I pretty much understood Unreal is like subtance : Doesn’t like overlapping Coordinates, but what if I’m doing a face texturing and cut in halves to gain space and resolution ?
I think I need to have a full explaination of what the heck is going on, because I’m completely lost, comparing to my old pipeline, and I wish to know what I’ll have to learn to change it. Because I’m used to make my UVW unwrap “by hands”, and I mean by that I do try to make the puzzle work manualy to gain sapce and performance, and the way the forums talk about the matter for UE4 really bugs me. I have trouble wrapping my head around the pipeline.
For those who don’t really understand, I guess I’m talking about this : See the pics
Working on 3DSMax
I know Maya too so if you prefer explain on Maya you can but I’m not sure I will understand everything right away.
Thanks to all !
The workflow for UE4 is that the first UV channel is for your material, so that can be overlapping and doesn’t have much requirements. For lighting you need a UV channel where nothing is overlapping and everything fits in the 0-1 UV space. If your first UV channel is already like that then you only need the single UV channel which can be used for both, but if not then you need to make the second UV channel for your lightmap.
In 3ds Max, to make your second UV channel for the lightmap you would drop your Unwrap UVW modifier on there and then go to the Channel section of the modifier and set the Map Channel to 2 (the second UV channel). Then you can flatten your UV’s in the modifier (there’s automatic flatten UV though I recommend doing it manually to get the best results).
When you import to UE4 make sure to disable the option Automatically Generate Lightmap UV’s, and then it will automatically use the last UV channel for the lightmap.That option is on by default and all it does is take the last UV channel and run an algorithm to flatten and pack the UV’s to a new channel, so it requires that you already have a set of UV’s with the seams split and everything so it’s not really fully automatic, so if you’ve created your lightmap UV’s in 3ds Max then disable that option to use them.
Thank you very much for your response. I think I understand the concept now.
However I’m afraid that, after trying, I am more confused than before on sevral points now.
I made sure to make my FBX an Embed media, checked the options you evoked, so I’ll try to sum up my situation :
I’m trying now to import a FBX with two UVW unwrap modifiers, each one with a different chanel :
Should I collapse all thoses ? Is there a way to preserve my two channels in one ?
Do I have so make a special set with my materials ?
Here are some pics of what I deal with.
Thank you for your support !
EDIT : I would like to move this discution in the appropriate forum, should I just post something new ?
You can keep the modifier on there in your 3ds Max file if you want or you can collapse them and it’ll still keep those two channels on the mesh where you could view them again by dropping the Unwrap modifier on again.
Your materials can use the first UV channel
It looks like you need to re-import the mesh to make sure that it’s importing your updates to your UV mapping and to make sure it has the second UV channel.
Also, I can move this to the appropriate section
Thank you very much. I’ll go back to all of this a bit later and try what you suggested, and try to have only one UV modifier ? Maybe ? But that would be a problem for a 3DSmax forum I guess.
I already reimported several times without fiding a way to make the two chanels visible. I guess i just don’t know how to handle channels at all ?
I’ll edit later to update you on this.
Try deleting the object from UE4 and importing it from scratch.
It’s better for performance/memory if you use one UV map, and if you can make your UV’s work for both your material and lightmaps then that works out well.
Ok, I got back to it.
I redid my unwap from scratch with the simplest method ever so that nothing can overlap. No longer lightmap issues, just my original problem.
It seems that no matter what I delete or not, I cannot make Unreal read my UVW Unwrap Settings.
I do tick Embed Media in 3DSMax,
Windows 3DStudio does read my FBX without any problem, texture included.
I don’t generate lightmaps automatically,
So, I assume i missed something somewhere.
Any ideas ?
Thank you so much for the support @darthviper107 . I learn a lot thanks to you no matter what.
Try using Unreal Studio, we handle all that for you.