ZBrushCentral

Normal Map Problem

ZBrush Usage Questions
#1

Hello everyone,

With the current problem I’m having…I’m not sure if it is related to how Maya interprets my normal maps or if it’s Zbrush’s settings…
Anyway, basically whenever I create a normal map in Zbrush and export the low-poly model into Maya (2012) and apply that said normal map - I get very harsh bumps and an overall ugly shape that looks nothing like what is intended.

So, my questions are:

Do I have to adjust anything in Zbrush so that my N maps are created properly?
Do I have to change any settings in Maya so that my map is perceived correctly?
Or should I just create my map in Maya instead?

Thank you for your time.

#2

I dont have Maya but i made this search(Normal Map and Maya) and here is:
sorry!!! search Normal Map and Maya please
hope you find the answer

#3

I’m afraid the link doesn’t work…

#4

invert your green channel on your map as well as flip the entire map vertically. You can do this in Z or any other image editor.
make sure you change your bump node to a tangent spaced map (defaults to bump)

#5

Or should I just create my map in Maya instead?

If you’re rendering in Maya, its best to bake the map in Maya because then the tangent basis will be synced up.

#6

Thank you everyone for your much needed help - I was finally able to to get my maps to work.
But if I may ask, why must the green map be altered? Is it just a channel which Maya can’t perceive properly? Or?

#7

Maya sees the channel just fine. The problem is that different renderers/shaders treat the values differently. Some like the y value going one way, others expect the opposite. X (commonly the red channel) is less rare, but even that still happens. And sometimes the values are in completely different color channels (so green isn’t always y). There’s no real standards, and the differences can be found in other areas such as the math used to calculate the tangent basis (which is why often a map baked in Maya would look best in Maya, since since they’re going to be calculating everything identically). On the other hand, until recently 3DS Max would even calculate it differently between baking and rendering which would cause inadequate results unless using custom shaders to correct this. It’s reasons like these that led to zmapper being reduced in zbrush, since you cant create a map that pleases everyone.

Most bakers should come with the ability to flip the channel to your specific needs, and good shaders tend to also include options that let you quickly invert the channels as well.