The normalmaps always have the vectors of one axis (red or green) showing the wrong way.
I am using the latest update of Photoshop CC but im having this issue for at least one year now.
I tested this extensively with several 3D-Programms.The Easiest way to test this, is to create a white canvas with a rather large and smooth black dot in the middle. Filter>generate Normalmap. Load the image in your 3d-Software of choice. Move a Point light above the plane thats holding the Photoshop normalmap. You will see the light reflecting in the wrong direction on one axis.
I am using the latest update of Photoshop CC but im having this issue for at least one year now.
I tested this extensively with several 3D-Programms.The Easiest way to test this, is to create a white canvas with a rather large and smooth black dot in the middle. Filter>generate Normalmap. Load the image in your 3d-Software of choice. Move a Point light above the plane thats holding the Photoshop normalmap. You will see the light reflecting in the wrong direction on one axis.