Normal Map from texture. How?

[ryoslilbandit]

Hi everyone,
I have a basic model , happily textured, and I want a normal map for it. I know how to create them from high poly in zbrush/ xnormal, but how to I make a normal map from the texture?
I want the map to follow the marks in the texture, so the shadows look like they're coming from the cracks in the wall.
How would I go about this? I have a very (VERY) basic knowledge of Zbrush, just how to import, sub-d, sculpt, export, get normals.
Is there anyway to perhaps, texture inside of Zbrush/ Mudbox, using my UV map for the object, and sculpt WITH the texture?

I'm trying to explain it as clearly as possible haha. I don't really know how to go about it, so if anyone understands this, please help! I will sing your praises from the highest of metaphorical mountains.

Thank you!

[damaggio]

I think most modelers would sculpt in zbrush or mudbox and extract the normal maps and use  a back and white version of the texture as a bump node to apply over to add more subtle detail...so it's like a normal map on the shader and a bump as well....same with displacement, you can add a bump on top of it.

[hapzunglam]

Use either nDo , crazybump , substance designer , bitmap2material to convert colour maps into normal map.   Im not sure if you can still find nDo1  anymore.  It used to be a free photoshop action.