Applying Object Rotation to 1 Axis Only

Hello everyone, I was wondering if it was possible to apply rotation to 1 axis only.

Why am I asking? See below:

When exporting from Blender to Unity using .FBX files, in order to get the meshes into Unity with no rotation (0,0,0), you have to rotate all objects -90, apply rotation, then add 90 and export. The problem is, since apply rotation zeros out all axis, if you have a object that was rotated say 45 degrees on the Y, when the meshes arrive in Unity, that program thinks the object’s local Y axis is 0 (when in fact it is really 45), and the objects becomes exceedingly difficult to work with since both the global and local axis are no longer aligned with the object (making basic things like rotating the object very difficult).

So, if rotation could only be applied on 1 axis (say the X), it would allow for at least some of the axis to be correct both globally and locally, and let other axis stay rotated so that Unity knows where the local axis really is (even if Unity’s rotation and Blender’s rotations do not match).

The exporter should have an option to set the destination’s axis orientation so that the correct end is up in the exported file. It should be over on the left side of your screen as you set up your export.

There are still problems with that as well. Using say Y forward Z up, the individual objects end up being rotated by 90 degrees, placing their local axis in the wrong directions. You can rotate the objects in blender to get them to face the right way, but then they end up with rotation in Unity (which again puts their local axis in the wrong places). Its been a problem for years, and aside from rotating, applying then counter rotating, there seems to be no other solution. So that’s why I was looking into just applying on 1 axis.