Is anyone using Modo with UE4, it seems anything above a single UV channel is causing issues with lightmass? Everything is fine until you bake.
Are you trying to setup your lightmap UV’s or is it an issue that you don’t have any?
Let’s see if I have this right? So do you need to create a secondary UV for lightmaps (In your modelling program of choice) for every submesh with either a box or planar unwrap?
Or can you just generate Lightmaps like you can in Unity? I just want to make sure my workflow is correct before I start reporting issues…
You need a secondary UV layout IF your first UV layout(the one you set up for texturing) has overlapping faces. Most of the time that’s the case since you may want to stack some parts of your UV’s if you are using tiling textures. But if you prepare a single UV layout that suits both texturing and lightmapping then you dont need a second UV channel. However Modo is not exporting more than one UV channels as we found out at AnswerHub.
Hi Jacky, yeah I understand fully what you said on Answerhub. I’ve reported it as an issue to Modo and I’m awaiting for their response on the matter, then again I’d also like to try and make some progress whilst I wait for a reply from the sales guys about Enlighten also.
I was intrigued to see if anyone had found a workaround in Modo, something quick to set up the scenes and start moving with it. Whilst UE4 isn’t my primary focus as of the moment, I’d like to keep it open as an option…
Modo user here. What version of Modo are you using? Modo can import multiple UV maps just fine with FBX 2006/2010/2013. AFAIK In the past Modo to UDK with Collada had problem with multiple UV maps. Try creating a cube and create 2 UV maps with different arrangement, a cube should have 1 UV map when you create it for the second one you can use UV Projection Tool>Projection Type> Atlas and export to UE4 - tell me if you see both UV maps. BTW this section of the forum is not for asking for help, you can post that in Content Creation section of the forum. If you can post up the one of the mesh that as lightmass problem , I can take a look at it. Are you newbie to UV editing?
UE4 has a tool to generate a lightmap, but it doesn’t do as good of a job as Unity and sometimes you get a crashing bug, and sometimes it just won’t do it. It’s best to do it by hand.
However, there’s a few rules about lightmap UV’s that you have to follow–the UV’s have to be within the 1.0 x 1.0 UV space and they can’t be overlapping or inverted. If you do a box or planar unwrap you won’t get correct mapping because things will overlap.
Hi Kim, not I’m not new to it… We have 28,000 assets that worked fine in Unity and CryEngine, also some of our artists used to work for a well known publisher. So we are really scratching our heads on this one?
In fact as far as I remember, these assets worked fine in Unreal 3??
We have already tried exporting a house with a single UV map and it works fine, we used Atlas 2 projection. We tried exporting as 2010 which flagged errors with version, so we exported as 2013 and no errors are flagged up…
It’s only when we subdivide meshes with multiple UV’s things get weird.
I’ll not post assets on a public forum, but if you want me to send you a PM with an asset let me know…
Great, I just wanted to make sure what your experience level was. If you can email the problem asset I’ll take a look at it. naka_256 at hotmail dot com
[Thread moved to the appropriate forum section]
It’s also necessary to tell UE4 to use the second UV channel for lightmaps, it’s easily forgotten and takes a bit of digging to find where to do it.
Here’s a visual aid:
Hi all,
I’ve been having a slightly different problem when I import an fbx mesh from UE4 back into Modo to do some editing.
There seems to be 2 channels taken up in the UVmap slots as seen in the attached image.
I can’t seem to delete the blank one or modify it in any way. (eg. I can’t move my lightmap/textures up into the 1st two channels)
Please help! 
Select the UV map and enter “vertMap.list txuv {}” in the command bar. It will then highlight, and you can now delete / rename it.
Hey, you said that MODO worked with cryengine? Could you explain your workflow?
I tried MODO an Cryengine (Steam version) and it didnt work very well together, even a simple boxmesh. So I stick to Unreal Engine. With Unreal, things just works 
EPIC have a video where The Foundery uses MODO and Unreal Engine shaders here: Creating Art with MODO & UE4 | GDC 2015 Event Coverage | Unreal Engine - YouTube .