Epic's projects meshes UV question

Good day all,
Why in the Epics learning projects the Meshes have very often the channel 0 UVs with islands out of the UV boarder (in red)? Shoudn’t this be considred as a modelling mistake?

Thanks all boyz and girlz

This is standard practice, normally it means the mesh has a tiling texture or has mirrored pieces. Unclamped textures just repeat infinitely in the UV space at an interval of 1.

There are times when you will want to keep everything inside the 0-1 UV space, such as lightmap UVs or possibly when you’re using the UVs to store other data such as for vertex animated textures or pivot painter. But for regular surface textures it’s fine.

Thanks Arkiras this was very helpful.

Your second UV channel is often the channel used for lightmaps which do need to remain within the 0-1 UV space