Normal map seams in Maya
polycounter lvl 10
Hello everyone,
In my first attempt at baking a normal map from a high poly source (as opposed to converting 2D height maps to normals), I sculpted a basic rock in Mudbox; nothing fancy.
I saved out the high poly mesh as an obj to use in Topogun where I created the low poly mesh and from there, imported the high poly and low poly rock into Maya.
The low poly model is flat projection mapped and a UV cut is made around the middle, creating two shells. Both shells are averaged out on smoothing.
At that point, I attempt to produce a normal map from the high poly source. Unfortunately, there is a highly noticeable seam that's created as a result.
I have tried hardening and softening the seam line to no avail. Even took it into xnormal to see if I can produce a better bake but the seam is still visible. I'm not sure what else to try.
As a last resort, I could use a 3D painting application like Bodypaint to clone stamp the seam area to conceal the harsh line break. While this could work given the random nature of the sculpted geometry, such is not always the case so I'd like to fix this first in Maya if I can.
I have also provided the source files of the high res and low res rock mesh models if anyone would like to diagnose the problem on their own system at: http://www.mediafire.com/?hukczh5y8ftbbgw
Thanks in advance.
In my first attempt at baking a normal map from a high poly source (as opposed to converting 2D height maps to normals), I sculpted a basic rock in Mudbox; nothing fancy.
I saved out the high poly mesh as an obj to use in Topogun where I created the low poly mesh and from there, imported the high poly and low poly rock into Maya.
The low poly model is flat projection mapped and a UV cut is made around the middle, creating two shells. Both shells are averaged out on smoothing.
At that point, I attempt to produce a normal map from the high poly source. Unfortunately, there is a highly noticeable seam that's created as a result.
I have tried hardening and softening the seam line to no avail. Even took it into xnormal to see if I can produce a better bake but the seam is still visible. I'm not sure what else to try.
As a last resort, I could use a 3D painting application like Bodypaint to clone stamp the seam area to conceal the harsh line break. While this could work given the random nature of the sculpted geometry, such is not always the case so I'd like to fix this first in Maya if I can.
I have also provided the source files of the high res and low res rock mesh models if anyone would like to diagnose the problem on their own system at: http://www.mediafire.com/?hukczh5y8ftbbgw
Thanks in advance.
Replies
I just applied your normal map to your model in marmoset, and didn't see any issues, so I'm gonna assume that everything is fine.
Normal maps are dependent on the angle of your UVs. The "seam" in your normal map is there because you have you have a seam in your uv's. Since there's a seam in your uv's, the uvs are at two different angles at that point. Since the uv's are at two different angles, the normal map has to look different at those points to function correctly.
Hi Dirigible,
I rendered out the low poly rock using just the normal map applied on a basic grey blinn material and there is a visible seam, still.
It's possible that the viewpoint or some other display aspect of maya may be misconfigured. If so, hopefully I'll get a pointer in the right direction.
Does your render produce a seam at all?
Your seam looks more like the green channel is incorrect. I don't see why it would be, but try reversing it in photoshop. Go to the green channel and hit ctrl+i.
Reversing the green channel helped.
There is still a seam but it isn't as prominent in certain areas compared to before. Thanks for the tip.
I take it seams will always be a fact of life for normal bakes on organic meshes and that clone stamping the seam area is a common workflow for most?
No, definitely not.
jpg compression makes it worse, which is why most people use targas or pngs for textures.
Putting edge-padding into your normal map bakes will also help prevent seams.
Clonestamping is a very very bad idea. When you plug your normal map into your diffuse channel it is completely normal that you will see seams. Clone-stamping those seams away will ruin your normal map.