I hope I don't seem like I'm spamming but I've looked around this site and google for advice and non of it is really helping.
My problem is that if I use the normal map I baked from my high-poly rock model (2nd one in the image) then the normals are completely fine. If I use the normal map I created from the diffuse using Bitmap2Material and specify that it's an OpenGL normal map I still get these blocky shadow areas on my normal map but the map itself is totally fine:
(I've intentionally used a jped in this example so I can upload, but the real file itself is a PNG, about 4.7mb)
Anyone know why this is happening and how I can fix it? The reason I want to use the normal map generated from the diffuse is that it contains more of a bumpy texture and it looks nicer than the baked normal in comparison.
Here's the normal map working totally fine in the texture program:
Solutions tried: smoothing edges, vertecies, faces in edit mode. Setting faces to smooth shaded. Opening my normal map in photoshop and re-saving it to see if it alters the data somehow. Changing from colour to non-colour data. Playing with normal intensity.