How to UV Unwrap (by adding seams) ?

So I was modelling this in Unreal and I would like to uv unwrap it in Unreal too. In blender, as far as I know, you simply mark the seams at the “edges” to tell blender how to project the uvs. Then you unwrap it and mark more seams until you projected the entire object the right way.
However if I click on Edit UV seams in Unreal 5.4 and mark the seams and then unwrap it again it seems like Unreal isn’t really caring about my seams. Is there something wrong in the way I think ? What am I missing ? (I also couldn’t find a tutorial on YouTube about Unreal UV Unwrapping with the help of seams)

Edit: Also in general it seems to me like that edit seams function is behaving strange. Maybe it’s a “me-problem” but somehow I can’t edit seams at places where there is clearly an edge visible but Unreal isn’t giving me any “dots” to connect in that position.

Thanks for any help

To hide edge between islands.

  • make sure smoothing groups are same for both sides of seam
  • make sure all islands on lightmap texture have at least 2 texels between, so light does not leak over.

Hourences had nice explanation for what unreal wants but by now it is really ancient tutorial (ut3 and udk era). My knowledge about meshes is also bit rusty. :wink:

I am not quite sure if I understand what you are talking about and if you understood what I was talking about… (no offense)

Why are you talking about lightmaps if I am talking about uv unwrapping ? And what are lightmaps ? I watched a lot of uv unwrapping videos and didn’t hear a single time about lightmaps…

You are complaining about seams, and seams are visible because lighting is not smooth around seams edge.

And reason for not smooth lighting are uneven smoothing groups or lighting leaks over seams.

No? I am not complaining about visible seams.
I am complaining about the UV Unwrapping feature in Unreal by manually marking seams.

Yes i got that now. :smiley:

It is just a plugin in unreal, use blender for it.