[SOLVED!] coordinate-handedness confusion

[Roland Melkert]

https://imgur.com/a/EwC2rc0

To go from right handed (LDraw) to left handed (UE4) you need only to flip one axis, I think flipping the Z one is best.

But you need to do that after the whole model is loaded and assembled/flattened into a mesh.

After the z flip you need to do an additional rotation to compensate for the LDraw neg Y up and Unreal's weird z is up orientation.

But the z flip alone should give you a clean model, it will just sit on its side or something without the additional rotation.

Even without the z flip it should be a solid model it will only be mirrored.

So the most important thing is to make sure you assemble the LDraw data correctly, before worrying about the coordinate system.