Visible 'seams' on character skin in renders

andya_b341b7c5f5

I am noticing some visible lines on character's skin in renders.  Two examples attached: one is on over the knee and runs on down the inside of the lower leg (the black line); another is on the inner thigh ( the pale line).  I have also seen them on shoulders, around biceps and on forearms, and on multiple characters' skins.

I am guessing these are where the edges of image textures meet, but some seem strange for that e.g. around the bicep.

Are these avoidable, and if so how?  They are bugging me no end.  Any suggestions appreciated.

kaotkbliss

Are the skin texture, character, and UV layout for the character all the same?

Leana

What are the surface settings on the material zones on both sides of the seam? It looks like there's one side with bump, normal or displacement and one side without it (or with a different value)

andya_b341b7c5f5

Thanks for the suggestions, put me on the right track.  Somehow there were a number of bump maps for Torso assigned to limbs, which account for these lines appearing in the middle of surface as well as at the edges.  I have assigned bump maps intended for the limbs.  I would swear I did no more or less than use the all material preset on this character, or I'm sleep-Dazing and not aware of making this error.  Part of the problem may be that the texture files are inconsistently named, so the ones relating to limbs are not all listed together and neither are the torso files - the author can't decide whether to user dashes or underscores, and seems to have changed preferences over whether to start the filenames with an abbreviation of their own name.  This make it harder to locate all the files with names containing 'limb'. Anyway, looks to have resolved that puzzle, thanks.