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Bad, broken, vector-like normal maps in Zbrush! - Resolved

ZBrush Usage Questions
#1

Hi everyone. Im improving my skills in zbrush, so i decided to quickly model something in sub-d, in this case it’s an eye, subdivide it in zbrush till the 6th level and sculpt some detail on it.

The problem consists in generation of normal-maps. I did it before, with models made in zbrush using zspheres, i did it with zbrush primitives which already got UVW mapping coordinates, and i hadn’t problems. But now, i’ve modelled my eye in 3dsMAX 9.0 Sp1, unwrapped it using a really fast method with UNWRAP UVW modifier, exported it in .OBJ format with quads preserving the mapping coordinates, and imported it Zbrush.

eye1.JPG

I tried a lot of options… i cant get a good normal map from any of the objects made in 3dsMax 9 and exported in obj format. Maybe the problem is in the version of the obj format. Maybe it’s structure changed since the 9th version. I wanna hear some opinions about this problem. Maybe someone already had such a problem. Thx in advance.

Attachments

eye2.JPG

eye3.JPG

eye4.JPG

eye5.JPG

eye6.jpg

#2

This looks like a UV issue. Looking at the map, part of the polygons appear to be in an adjoining UV space. That would create a problem. What happens when you press Tool>Texture>Uv Check? Does the model turn red, or partly red?

#3

The problem is that any object uwrapped in max and exported using the obj format … gives me almost the same result when trying to generate normal maps…
That’s what i get when i check the uvw… seems like i got a problem with some of the polys but not all the geometry… I think that’s not the problem…

eye7.JPG
eye7.JPG1280×800 91.5 KB

#4

I think you have part of the mesh hidden. The entire mesh needs to be visible to create maps inside of Zmapper. Or you get…well, what you have. If you have multiple UV regions for that mesh you need to break the object into a subtool for each region. Then generate the normals.

#5

goast666 - well, i kinda know what i’ve modelled))), when i try to generate the normal map for the whole object, a windows with 5 steps pops up saying i should go to the uvgroups and make visible 1 part of the mesh at a time using the ctrl+shift+click shortcut. I have one object and 1 uvgroup… i have no different parts of the mesh, i dont have parts of the mesh hidden. When i generate the normal map i have my model visible in the viewport… there’s nothing hidden.

#6

for 1 thing your UV’s are too close to the border. That is where that red line is coming from. Try to move in the UV’s a bit…4pix padding edge at least. If that doesn’t fix the problem see if you can upload the file and let us have a crack at it.

#7

did you actually break the mesh at each UV region…or just hide it. I know you just said nothing is hidden…but that is what a normal map looks like when parts of the mesh are hidden. I’m really not saying this to be an ass. I just know that what Zbrush tells you to do (the 5steps) is wrong.

#8

it sounds like you didnt actually apply any real mapping coordinates to the mesh. after you make a mesh, you have to apply uvw map modifier and then you can do the unwrap modifier. try that, and dont forget to reset the zform before exporting to an obj.

#9

goast666 - thx for the tip with the red line :slight_smile:

robertrageson - some people do a rough uvw mapping by applying and UWV MAP modifier and after that doing an unwrap. Im used to do the Unwrapping from the beginning. Thats the same thing. In both cases u have UVW coordinates.

The issue has been solved by resetting the XForm))) . Thx alot guys.

#10

Just a note for anyone else that runs into this. I came across this problem months ago, its not a problem with zbrush as the problem can be seen when importing things into the Unreal Engine too.

If resettingthe xForm doesn’t fix it. The only other way I have found is to export the model as a .3ds and then reimport it into max.