Normal map colours and vertex painting

[FONT=Times New Roman] I am about to bring my very first normal map (whoop) into UE4 from XNormal, but before I do so I have two questions.

Firstly, I understand that each of the four colours (apart from the background, obviously) represent either left, right, up or down respectively. I have heard these represent different colours from programme to programme. Which direction (for lack of a better word*) does each colour represent in UE4 normal maps?

Secondly, in several tutorials [SUP] 2 [/SUP] I have watched about vertex painting, I have come to the understanding that a number of loose vertices is needed on each static mesh in order to effectively use vertex painting thereon. My question is, would having such loose vertices affect the quality of my normal maps? Would it, therefore, be more useful to add vertices after creating my normal map; or would this not make a difference?

Thanks for any replies in advance :heart:

*I would much appreciate if anyone could post the word I word use here.
[SUP] 2 [/SUP] for example,

The normal map colors represent X/Y/Z angle, the blue channel is Z but since you won’t see anything happen with that it’s always 100% blue. Some games or 3D software might have the red or green channels switched or they might be inverted, I’m not sure if Xnormal uses the same interpretation that UE4 uses.
When you import to UE4 make sure you set your normal map to use normal map compression–otherwise it will not render correctly in the material. You can have it automatically detect the normal map by adding _normal to the file name.

As for vertex painting–yes, you need some vertices on a surface for it to be used, the density will determine how small you can paint. This increases the amount of memory used, and as far as whether it can affect your normal map, it can do that since it can change smoothing. For example, if you have a curved surface and you subdivide it more to add vertices it will change how that curved surface will smooth. If it’s a flat surface like a wall or the floor then it won’t affect the normal map.

[FONT=Times New Roman]Thanks so much. :cool: