I'm American, amadeux, and was probably speaking English well before you were born. Your original post consisted primarily of "Here's some images. I think something's happening with my normals around Z=0. What's wrong?" You don't mention what API you're using and, with so little else to go on, I asked questions to try to get more information, which you seem hesitant to provide, looking for something of a technical nature. You assume everyone will know what you're doing and how you're doing it when you say you're "calculating normals for adjacent triangles," "disabling the calcs for the adjacents" and "using a normal buffer," seemingly assuming people are psychic. You post some more pictures showing the same behavior as the previous images and.. finally post all of 7 lines of code extracted from some routine, saying only (after being asked several times): "The indexing is correct."

The likelihood of someone looking at some images and a few lines of code, and pinpointing the problem is slim-to-none. Without any further information, I can only make general suggestions.

1. [s]Ensure there are no duplicate vertices along the Z=0 line[/s]. Oops. Sorry. You said the indexing was correct.

2. Check the data is being loaded correctly.

3. Check that the math functions such as vec3Add, vec3Subtract, vec3Cross, etc., are correct and you're using them correctly.

4. Check the logic and code elsewhere (other than the 7 lines of code you posted).

5. Check that all your variables are initialized.