Baked Normals "sliced up"

Hello folks

I’ve modelled this
http://img93.imageshack.us/img93/7699/bshighpoly.th.jpg
http://img48.imageshack.us/img48/7699/bshighpoly.th.jpg

and then I’ve made a lowpoly model of the same

http://img50.imageshack.us/img50/3075/bslowpoly.th.jpg

But, when i try to bake the normal map on the lowpoly model, I obtain this

http://img94.imageshack.us/img94/3329/bsbakenormals.th.jpg

the faces of the normal seems sliced. I’ve tried to recalculate normal, and there are no lights in scene.

Can anyone give me a hint? will be apreciated!

thank you!!

Your problem is probably the mirroring. You’ve got a right side and a left side, and they’re both trying to bake their normals to the same UV space. Poor Blender doesn’t know what to do and just assigns the normals from one side to one triangles, and the normals from the other side to another triangle.

So what you want to do is bake the normals from only one side. Now, Blender only bakes normals from polygons of which the UVs are in the 0-1 space (that default square), so UVs placed outside get ignored completely. But the end result does tile. So just move one half of the UV to the 1-2 space.

That means you select the UVs of one half of your model, the part you want to be mirrored. Press G and offset them by the size of the image you have in the UV editor. So if you have a 512x512 image, just press G, 512. They should be ignored in the baking process now, but they’ll still share the outcome.

It should be noted that Blender, as far as I know, can’t actually display models with mirrored normal maps properly, so be sure to test the end result somewhere else.

Great!!!

now works!! thank You!

Can I make you another question? how can I solve the aliasing artifacts in the baked map? It’s really annoying me because I tried to switch to “Anti” and “Premul” in the image properties panel, but without any result.

Thank you in advance!

I think that blender always has aliasing on baked maps…somebody correct me if I’m wrong but there is currently no fix.

Hi,

I guess that, as a workaround, you could render the baked map twice as large and scale it down after.