Normal Map Hiccups
I've perused a number of threads here and in a handful of other locations across the internet, and while there is a wealth of information available on the subject, none of it has been sufficient to address the specific problem I'm encountering with my normal maps, so hopefully the Cow Community can help.
I'm transferring normal maps from one model to another using Maya 2008's "Transfer Maps" function in the Rendering menu set. The normal map from my high poly mesh goes to my low poly mesh without difficulty, and looks pretty darn good, except for one thing: weird grid lines. The normal map has grid lines where the low poly faces/UVs are. (I unwrapped them in UV Layout, so they're pretty much the same) I've attached an image as a reference so you'll see what I mean.
1. Hi poly mesh, no texture view
2. Hi poly mesh, textured
3. Low poly mesh, no maps, just a blinn
4. Low poly mesh with normal map transferred.
5. Close-up detail of the low poly mesh showing bizarre grid lines.
6. The normal map in Photoshop. Note that the displacement is smooth and clean, just the faces/UV lines are whacked out.
I did about 6 hours of reading over the last few days in an attempt to figure out why this was happening, and have tweaked numerous settings. I've increased the sampling from preview to low to medium and changed the transfer from world space to object space, all to no avail. I even softened the normals on the low poly mesh before and after transfer, but that only helped a little bit. I read a few websites with some amazing information about normal maps that definitely seemed relevant, but I don't know how to apply them in Maya. I'm trying to avoid learning a third party product like xNormal if I don't have to. Any help that anyone can offer would be greatly appreciated. I'm hoping I'm just missing a simple setting!