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Blender to unreal4 workflow / UV mapping / lightmaps / baking textures

Hello everyone. I work a lot with blender and there with images from the real world i use to model and texture my scenes. I´m actually figgering out a good workflow to use these scenes in ue4 for realtime cinematics. how is the best workflow for that? i use also the send to unreal addon but i have several issues with the material export, overlapping UVs and so on… any suggestions?

Don’t use blender for materials. Make the materials in engine. Preferably off a master material you made your self that uses packed images to lower scene costs by baking stuff down in blender.

As with anything, there isn’t a specific workflow to follow that will always work.

To map UV border lightmaps properly, turn on pixel snapping at corner, and set the material texture to 128 or less - depending on the item size.
unwrap. Select one island at a time. Press G For it to snap. Make sure you have no overlap.
On models where this isn’t possible (1000 faces of that and you’ll be crying) just unwrap and leave it be.

  • note that it’s important to have the pixel matching on anything that needs to have precise shadows like walls which are also usually 10 or so faces max.
    Possibly decide right away what order your lightmap will come in. Unreal uses 1 (the second map).
    you can add a few more UV channels. Usually used to map normals differently on different parts of a mesh, or to provide animation maps via pivot / other crazy stuff you don’t need to worry about probably.

If you have overlapping UVs in your lightmap you either have no idea what you are doing (which is always the case even when you do), or you just cut the model wrong. Smart UV project can help fix it, but it will likely cause shadow artifacts if if don’t know what you are doing.
To tell you what you need to do I could probably write a 600 page book and still be completely wrong about a specific case.

To bake, it depends on what you are doing.
baking a normal map of a high def to a low def is easy. Baking mounding, trims, etc. Is not. Still this is more of a blender question/ issue. Watch tuts, ask in blender forums.
The end result is usually that you pack textures like metal Ness, roughness, and specularity into a single texture and use that single texture in engine with your master material.

Or that you use a less dense poly model with the normal map of a high quality one which looks visually almost the same but doesn’t incur the 1b polygon count cost that made it look good.

Trial, error, work, more work. And when you think you have something, scrap it and start over :stuck_out_tongue: