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Importing SketchUp Models - UV Overlap

Ok so yes I’m aware that Sketchup typically sucks when it comes to exporting models to game engines. However considering how fast I can model in SU some working compatibility would be a huge life saver. I’m hoping that I can find a successful workflow solution that will prevent the UV overlap issue that occurs when importing Sketchup models into UE4 and building the lightmass. My main interest in this functionality would be for Arch viz however I would also find this helpful for the game I’m working on too.

Here are some screens to illustrate the problem. The materials look fine until the light is built which subsequently causes chaos with random UV patterns, otherwise the materials just appear very dark. I have also tried exporting as .fbx and .obj using various import options, reapplying textures using Cinema 4d and repacking the UV in 3Ds to name a few attempts and I’m running out of ideas. :confused:

http://s28.postimg.org/ycoq5hmyj/2014_08_30_18h01_16.png

http://s3.postimg.org/q06bam19f/2014_08_30_18h09_03.png

I have been reading lots of threads etc on this but I’m hoping someone has already figured this out. Thanks in advance for any help. :slight_smile:

Sketchup -> engine never seemed to work out well for me, I’d always unwrap the UVs in Blender or Max. My old workflor was Sketchup -> Max -> Unreal. Maybe pass it through blender to make sure the UVs astay friendly?

Hi Owen,

As Chance was suggesting you’ll need to setup some UVs in Max/Blender or a 3d Modeling software for the most part.

The problem isn’t that the UVs are wrong though, it’s that you need a second UV for lightmaps. You may be aware of them or not, but these are important for Static objects because lighting information will be baked into a texture that gives great shadows with zero performance hit at run-time.

If you don’t want to download a larger program like Blender or Max you can give RoadKill UV a try. RoadKill UV website.

I’ve recommended this for other users as well and they’ve seemed to get some use out of it. It’s a way to edit the UVs without needing an entire modeling suite and it’s simple enough to learn, especially for just laying out a simple lightmap UV.

Here is the intro vid for it just to see if it’s something you may be interested in.

https://youtube.com/watch?v=EfY_zbOkFZ4

For some more information that may be handy for whatever program you decide to use for your lightmap UV layout, World of Level Design has a comprehensive tutorial series for lightmapping in Unreal.

These tutorials are from UDK/UE3 but they are still relevant to UE4.

World of Level Design: Lightmapping

If you have any questions feel free to ask!

Tim

In what format did you export your work from Sketchup? I’ve tried FBX and Collada and I can’t find a consistent workflow. It seems that randomly some models work and others don’t. I’m trying to export some stuff from Google Maps/Earth.

I heavily use Sketchup and the workflow is more or less fine for me. If you’re importing walls, floors and ceilings then it’s pretty much a direct port over to Unreal Engine 4.5 and up (thanks to the imrpoved auto lightmap UV). If you’re using an older version you’ll have to resort to making a lightmap channel for your fbx file.

For more complex or more organic objects you’ll inevitably have to manually lightmap them. Half of the time you can get a away with just automatic flattening though.

I think this free tool from Sketchup extension warehouse solved the problem :slight_smile: !!!

https://extensions.sketchup.com/en/content/sketchuv

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Hi fractalbuddha! Could you explain how to use this extension? Do we need to export each block/model of the escene? Or is it work for the entire scene?

Hi,

when the meshes are big there is more chances to have UVs Overlapping. When you import, you should not group them. You can see on the extension page how to use it. Never use the spherical rap. It generate too many meshes.