Why is actor / material rotated by 90 degrees by default?

I have a simple texture, just a small arrow pointing upwards. Then I created a material out of that texture:

However, when I set this material for a small plane in the world, then the arrow points towards the negative Y axis:

After I set the rotation of that plane on the Z axis to 90 degrees, then the arrow points towards the X axis, as expected.
That leads me to two questions:

  1. Why do I need to rotate the actor by 90 degrees (or the material, I guess), why isn’t it pointing towards the X axis in the first place?
  2. What is the desired way to handle that in general? Should I rotate the actor itself after spawning it, or the material, or anything else?

Thanks in advance!

+Y is forwards at least in the mesh edit/view default. In your case it’s not trying to point towards -Y, if you made a cube the front face would be correct pointing up, but the plane is the top not front face. There’s no wrong way to fix it, the orientation of the object, material, or UVs are all safe to change.

Thanks a lot!

Can you please, share a bit some about this. I cannot understand. Thanks and Regards, Jack Logan