Here’s a quick guide of how it’s done, might make a video in the future but was short on time.
Images in album: Guide for making and baking low poly for UE4 - Album on Imgur
Get your model.
Explode it into the simplest pieces.
Create the low poly parts.
Reuse stuff if possible to save time. (Note I did not use enough geometry for the side arms of the couch, look at picture 25 and you’ll see the issue. This could of been easily fixed by starting with more geometry along where the bars would go. I did not have this issue the first time in the above posts because I checked before putting the asset in the engine.
Shrink wrap
Relax just a bit so the geometry isn’t too tight or almost over lapping.
We are just unwrapping cubes here, it’s pretty simple, put a seam on every corner edge, and then remove 5 that would be in obvious places. That will help hide any tiling you do with a fabric detail texture.
Done unwrapping the 8 cushions.
Make sure it’s one smoothing group and there’s no hard edges. (Experience artists may want to put hard edges on UV seams, it can reduce artifacts on certain assets, but isn’t needed here).
No more hard edges.
Since we are using xNormal it’s best to use a cage along with the baking process, artists on Polycount have found Substance Designer/Painter do an amazing job even without cages, but I’d always suggest one if using xNormal).
To create a cage you take the low poly model and push it past the over lapping high poly model.
Make sure the high poly does not stick through the lowpoly anywhere. If it does, no detail will be baked there.
Triangulate and export. Also I cannot spell. Also make sure you are exporting the normals
Make sure this setting is checked in the plug-in settings, click the plug to get to these settings.
Import the high poly, low poly, and cage.
Where you add the cage.
Make sure Y- for UE4
Bake.
Recombine mesh and export for UE4.
Import normals and tangents.
Make sure the normal map imported as a normal map (it should if it has normal or _n in the name, you don’t have to do this ever time, but it’s good to double check if it’s your first time).
Create a material, I added a cavity map for AO, it adds a bit of extra shadowing on the wrinkles in indirect light. The multiple is there to adjust the strength.
You can check the light map UVs and make sure they look good. Set the light map resolution to 512.
Bake lighting and your done, this is showing the issue mentioned on step 4. The metal does not have any light map UVs so it’s completely black from the baked lighting. Didn’t have enough time to explain how to unwrap that.
Close up
Distance
I followed your walthrough but I must be missing something because when I look at the model in the editor I always see 1-2 pillows correct and the others like they have the normal flipped! to make more clear:
the “green pointed” is the one correct, the others are all flipped: if it wasn’t for the “drawstring” border I wouldn’t noticed it! I’ve already tried most of all possibilities: check the normals of high poly, low poly and cage (they are all correct); tried with many combinations of the swizzle coordinates (it moves the problem to other pillow but never more the 2 are correct at the same time) when baking the normals; tried (again) other softwares but nothing worked!
Quite tiring! ahahah
however thanks a lot for all the effort! your help here is really huge!
I’ll do it, but before I need to reach a result similar to the ZacD’s one or it won’t be useful!