Static Mesh Help "Combined Meshes"

Hey everyone,

I’m new to UE4 and would like some help with a static mesh issue. I created an asset in 3DSMax, it has 8 sections with each section having it’s own UV maps on Channels 1 and 2 (0 and 1 for Unreal purposes) When I import pieces individually I have no issues with my lights after a Light Build, however…when I import all 8 pieces together with “Combine Meshes” checked I have issue when building my lights in UE4. All of my UV’s are overlapped when I check the UV’s in the editor… I know that UE4 has the overlapping UV bug, but shouldn’t my asset having separate UV’s and Lightmap channels eliminate this problem? How can I tell Unreal to differentiate between maps of my combined mesh?

Thanks for any help.

I’m replying as I don’t want to see you discouraged from the lack of support after just registering. While I can’t visualize the exact problem your having, could you try importing the meshes and textures individually and group them?

Welcome to the Unreal Forums!

You can bring in all 8 objects into UE4 as a single model and it will maintain it’s material mapping but you will have to instance uv map channel 2 being used as the light map channel.

To do this select all 8 objects and in 3ds Max place a unwrap UVW on the stack. Set the mapping channel to 2 and assuming that you already have your light map UV laid out select “abandoned” when asked.

In the edit window you should see all of your maps from all of the 8 objects and there are a couple of things you can do.

1 use the repack UVW under tools.
2 Manually map each of the 8 maps.

Now when you import the maps of each object have their own space as a combined mesh but will maintain their individual material. Depending on the size of the object you might have to give the light map a higher than normal resolution.

Thanks so much for the reply and detailed instructions. I will try what you’ve suggested and go from there. Peace

Thanks for the reply, and help… it’s been a frustrating couple of days trying to figure this one out. Peace

FrankieV and Vallamost, thanks for the help and responses. My asset has imported as it should, light builds function properly. I slapped a UVW modifier on all 8 pieces, moved from channel 1 to 2 abandoning the previous UV’s. I then combined all lightmap UV’s into one channel “2” UV space…

Unreal ignores the overlapped UV’s from Channel 0 (Channel 1 in 3dsmax) and accepts the channel 1 UV’s (channel 2 from max) for lightmaps.

Hey John

If Unreal 4 takes the wrong Light Map UV. you can change it manually

Just go in the Static Mesh Settings and change the Light Map Coordinate Index
The Number represents the UV Channel which you can check in the Big Menu above.

i hope this helps