Cameras

Enable this option if you want to export cameras in the scene. Only Perspective and Parallel cameras will be exported.

Of the numerous other camera settings in Cinema 4D, only the Field of View (Vertical) as well as Zoom and the Enable Near Clipping clipping setting will be exported.

Normals

Select here if the exported objects should be smoothed (option enabled). This reflects the display in Cinema 4D with and without a Phong tag.

UVs

Enable this option if you want to export UV coordinates (only one UV map will be exported per object; if several are present only the first). Otherwise no textures will be shown.

Flip Z

This option should be enabled if you only work with the default coordinate system in Cinema 4D. The glTF export will then look exactly as in Cinema 4d.

The following applies for the various coordinate systems: glTF uses the right-hand rule (Z axis points to the front), while Cinema 4D uses the left-hand rule (Z axis points to the rear).

The difference is in the way scene objects are mirrored along the Z axis.