Blender 2.63 : Baking normals ( Artifact's )

[irishstorm]

Hey there!
I am having some trouble getting my normal maps to bake properly, I am following Arenovalis tutorial, modelling the M37. When i bake my normals i am getting weird artifacts like in the picture, i have tried converting the low and high poly mesh's to triangles and baking them, i have tried resizing the mesh, i have played with the bias and distance with little or no affect, I have made sure all of my normals are pointing the right way( I could have missed some, but i cant see any when i check) Just wondering if anyone has encountered this or could tell me what i am doing wrong, I would very much appreciate it!!!

I also should note that this is the first time i have tried baking something as complex as this!



High / Low poly Blends here

regards,
Chris

[Rammer]

When you bake try to remember that objects shouldnt intersect another object. That could be one reason that your normalmap could have artefacts.You could bake one object at at time

[Oki]

I had this issue too, it does seem like a Blender bug...I just baked the normal out via xNormal and it worked fine. I'm not sure if theres a bug report made for this however, I'll have a look tomorrow.

[Rammer]

I had this issue too, it does seem like a Blender bug...I just baked the normal out via xNormal and it worked fine. I'm not sure if theres a bug report made for this however, I'll have a look tomorrow.

I also see that you have some minor wavyness on your magazine on your normalmap?Insert an edge loop on the top of he magazine and one at the bottom and rebake and the waveyness should be gone

[metalliandy]

It's not a bug. It's because you have intersecting objects and/or that your bias/distance values are set up incorrectly
Basically what you are seeing is overdraw where one part of the model is being cast onto another incorrectly. The only way to fix this is to either explode you mesh so that the individual parts are apart from each other, set up the bias/distance so that you don't get it (which can be very hard/time consuming) or use a cage, which Blender doesn't support (yet).

You can make a cage in Blender for use in xNormal though. I use the following method.

1.Make a duplicate of your LP mesh (without the Edge Split modifier applied if you are using hard edges).
2.Add a solidify modifier to it and move it above the edge split modifier in the stack (if it is being used).
3.Uncheck "Fill Rim" and check "Even Thickness" and "High Quality Normals".
4.Change the "Thickness" into a minus number, so that it covers your HP mesh entirely.
5.Apply the Solidify modifier.
6.Go into Edit mode and select one of the faces of the outer most mesh.
7.Hit CTRL+L to select linked.
8.Invert the selection and delete the inner mesh, amking sure that all the inner mesh parts are selected and deleted.
9.Go back into Object mode and apply the Edge split modifier.
10.Export the mesh with UV's and Normals.
11.Done!

This will give you a cage for use in xNormal which should bake perfectly
Be careful to make sure that you don't change the topology of the cage by moving verts/faces manually because it will change the vertex order and xNormal will show an error.


The waviness on the barrel area is due to the amount of sides that the area has and isn't incorrect. It just doesn't look awesome on the normal map...depending on the angle of the gun, you might never see it. The best way to improve that part of the bake is to increase the number of sides in that area so that the low poly matches the high poly more closely which will give you less waviness.
The waviness is so slight on this though, that I doubt it will be seen that much.

Hope that helps!