I had a problem with visable seams on a human figure which I had baked a high resolution normal map to put on a low resolution model.
The seams appeared when I did a full length render to see the loin cloth I made for a Hawaiian man figure. Previous to that I had only rendered the face and shoulders to see the detail of what the guy and the texure map looked like. I read and watched a number of tutorials on UV textureing and visable seams. Lots of very upset people trying to get rid of visible seams. After painting over the textures in the joint areas, still no help, I tried the offset and size settings, and other suggested settings which just screw it up terrible, or no effect at all. I try painting further beyond the UV islands on the flat map in Gimp. I try painting over the seams in Blender texture paint. Those don’t help. The one suggestion I didn’t try was the bake the texture and redo all the seams and place the baked texture on the new unwrap and then repainting the baked on seams in Gimp cause they aren’t covering seams any more. Seems complicated. Then I discover if I turn off the normal map which I made from a high resolution sculpted model, the seams dissappear on the rendered image, at any distance. So it was my normal map that is putting in the seams, not the paint texture. I read up on normal maps causing seams, which seems quite common with most people saying there isn’t much you can do, just put the seams where they won’t be noticed, which is hard on my figure which is a
realistic Anchient Hawaiian man wearing only a loincloth. No place to hide the seams. I try expanding the blue and sort of pink area
around the edges of the UV island areas using Gimps clone brush, didn’t help. My UV islands look OK right up to the edges, no
discoloration, no artifacts. But the islands don’t abutt each other, as the arms and legs and the head are all cut off and and placed in a
well packed configeration. So they look ok to my eye, then I decide to see how they line up on the model, so I uncheck the color
texture map and choose the normal map for the body texture, and I uncheck the map from the geometry so it isn’t doing normals
anymore, and I click the color choice for the effect so it will show the skin as the blue/pink normal map, in otherwords, I wrap the
normal map around the model so the seams all line up correctly in place on the body, making a blue/pink model standing there his
arms outstretched. I go into texture painting mode and see the blue guy. Bam!! there I can see where the arms join the body and the
head joins the neck and so on. There are visible hard lined seams. The area is blue or shaded pink or whatever, but there is subtle
changes right at the edge of the lines, the blues are slightly different, the pinks are not quite the same, and it is obvious that they
change right there on the seam line. It is obvious. That’s what’s causing the visible seams. I grab Blender’s smudge tool and smudge
the two areas as they meet the lines so there is no more visible difference, I smudge across one way then back the other so each
side of the divide looks all the same blue, or the pinkish look in that area. Then I save the image by going to the UVmap and saving
the image, then I go back to the texture area and refresh the normals image, then change the normal map back to influencing the
geometry and not the color, then I render and AMAZING!!! the seams disappear! Some of the seams aren’t so obvious on the
model in the texture paint mode, usually they look uniformly blue, but I look at a photo of the seamed model and I can see where
there was a seam and I smudge the blue in that area, it doesn’t look any different but there must have been a slight unnoticable color
change because after smudging and switching the map back to the normal normal set up, it renders in the area with no seam at all.
Great! That’s how I overcame my seam problem. Of course your color map has to be touched up in the paint texture mode too, so
you won’t have obvious color changes at seams. I think part of the problem is tutorials that pick a real simple item to show how to do
UV maps or Normal maps or whatever, and don’t address the more complicated problem of a human or animal character that is 100
times more complicated. Sure it is easy to unwrap a cube, simple, then put a flat yellow on one side and a red on another. Easy!
Sure, wait until you get in the real world of actual characters that have rounded bodies and faces with a lot of subtle detail. Then how
do you get all that to match up? Not quite the same as doing a cube is it? Even the tutorials on doing a head and face don’t address
the problem of getting that head stuck on a body. Now there is a possibility when others mention blending the edges together across
a seam in a paint program that they meant putting the normal map on the character as a color map and blending using Blender’s
texture paint tool, but I didn’t catch that, and kept trying visually blending in Gimp on the flat texture map, which didn’t do much good.
Any way, hope this helps some of you who don’t automatically know what the others are talking about.