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Seams in my models (due to lighting?)

Development Discussion Rendering
#1

I have seams in my models. I created a 500x500x50 cube in blender for use as a building block and set everything to smooth shading with an edgesplit at 89 degrees so the edges would be sharp and exported it from blender to .fbx with face smoothing turned on and when I import it I have UE calculate the normals (since blender doesnt have a “tangents” option i dont think,only face normals) when I put my blocks together with no material or even with a seamless texture applied to the whole object I get visible seams. I’ve tried it in my main project with skydome etc. and in a blank project with nothing but a point light. Check out the pics. Any ideas? Edit: I also did recalculate lighting.

seams.png
seams2.jpg

#2

The normals might be wrong
Also, it’s best not to construct the level that way, you will end up with lighting issues between flat meshes and it’s not very efficient with a low poly mesh like that, you lose performance due to the draw calls.

#3

Seems like your normals are smoothed across the edges anyway. To isolate the normals from any lighting influence and make sure, you could switch the viewport to buffer visualization > world normal, the surfaces should be a single flat color. If there’s a gradient then somewhere in the conversion from blender to unreal the hard edges were lost.

I personally don’t use blender, but there are plenty of people who do, so there must be some documentation to find out which step in the export/import process caused your issue.

#4

I think I got it figured, gotta export in blender with flat shading in blender & no modifiers then export with face smoothing to ASCII. Or the same way with no export smoothing at all, in binary. Or the same with a 30deg edge split, with no export smoothing or face/edge smoothing.

Or smooth shaded wtih no modiers, no smothing export to ASCII, and binary works the same with with a 30deg edge split and no export smoothing.

What does not work: Smooth shaded, no modifers [Export ascii w/ face smoothing]
Smooth shaded, no modifiers, [export ascii with edge smoothing]
Smooth shaded, 30 deg edge split [export to binary with face smoothing]
Smooth shaded, 30deg edge split [export to ascii with face smoothing]
Smooth shaded, 30deg edge split [export to binary with edge smoothing]
Smooth shaded, 30deg edge split [export to ascii with no smoothing]

Took alot of experimentation to find that out though!