Need precisions about UVs

Hi,

I got troubles with ProceduralMeshComponent and UVs. They are flipped sometimes.

So what is UV exactly ?

Usualy texture’s bottom_left corner is u = 0 and v = 0 and top_left is u = 1 and v = 1.

How is it in unreal ?

In my code I have polygons where vertex.z = 0 so uv.y = 0 and vertex.z = 300 so uv.y = 1, but vertical uv is flipped.