Hi, I’m new to Zbrush and trying to edit a low poly character:
Folder contains only 3 files:
.obj
.png
.mtl
My problem:
I import the .obj + .png (as a texture map) then export it (after minor tweaks). Now the polygons are clearly visible on the model when I preview it in another software. Before it wasn’t, it was smooth.
I guess it has something to do with “normal maps”. But I don’t understand were it is, and why its lost after exporting.
Please help me! 
Dont think you lose anything
Depends on what “another software” you are using to previewing your mesh just “tell” him to smooth your mesh preview (normals)
Something like defoulth smoth, autosmoothing, vert.shading, aplaying same,single smoothing group…
The model was smooth before I imported then exported it from ZBrush. Same poly-count, and texture map. Something like this (but with textures):
Before > After
Any clue?
Your mesh hasn’t been changed. ZBrush doesn’t use smoothed normals so they aren’t included in the OBJ. As Modos says, you will need to apply smoothing in whichever other program you are using.
Alternatively export from ZBrush using the FBX plugin (if your app will import FBX). That has the option to include smoothed normals.
Ooh, now I understand! Thank you marcus and modos! 
Was getting frustrating, should have just asked earlier. Thanks again.
Should perhaps explain that normals are what the renderer uses to tell how the light should fall on an object. For “hard normals” these are calculated for each facet (polygon) and you get the result of the right-hand sphere in your image. For “smooth normals” the hard normals are averaged for each point of the model to create a smoothed effect - the result in the left-hand sphere. But you can tell that the geometry is still the same by comparing the outlines.
HTH,
Much appreciation I only started learning about shading this week; bump maps, normal maps, displacement… is a bit confusing but I’m starting to get a grasp now at least. Making notes helps.
Marcus…I have a problem with that export FBX out of ZBrush solution.
The OBJ file I have imports in Unreal Engine 4 at the proper scale but looks faceted even with normal map applied.
The corresponding FBX file imports in Unreal Engine 4 way too big but looks smooth.
I tried to use the Scale Master plugin to alleviate the FBX scale problem but the scale difference keeps occurring.
So far, I have to take into account the “Export” tab scale factor to resize my FBX export once inside Unreal Engine 4.
So, if the “Export” tab shows me a scale of 96.50562 for a 17.07 cm in “Y” dimension,
in Unreal Engine I have to change my scale to 0.09650562 for my model to show up at the proper scale.
Less than an ideal solution if you ask me, especially if at some point the “scale reset button” in Unreal Engine is clicked for any particular reason (somebody else might have to use my work).
Found this video hoping to fix this:
https://www.linkedin.com/learning/zbrush-tips-tricks/fixing-scale-problems-in-zbrush
But it doesn’t seem to work either.
It’s like FBX is in its own little world by itself !
Any suggestion ???
