Sky Box images need to be the same resolution

[Zwark]

I had a working sky box in libGDX that had texture sizes of 256 x 256 pixels except for the bottom texture which was 2x2 since it was rarely seen. With the bottom texture being 2x2, the gltf library renders a completely black skybox, but when I scale the bottom texture to 256 X 256 it works fine.

Skybox textures needing to be the same size wasn't obvious to me and a comment that the textures need to be the same size on the createCubemap method would have been helpful. It took me way too long to figure it out since I initially assumed I was messing up the skybox/environmentCubemap setup somehow.