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View Full Version : Zbrush to Maya normal mapping - help!

danshewan
04-28-2009, 08:31 PM
Hey guys,

I'm pretty new to generating normal maps in ZBrush, and I'm wondering if someone can help me out with a pretty persistent problem I've been encountering.

I've been creating base meshes in Maya, exporting them out as .obj files, then sculpting detail in ZBrush. So far, all good. It's when I start using ZMapper that the trouble begins.

Below is a shot of the kind of detail I'm trying to achieve - a simple wood grain effect, with some screws / bolts and what-have-you.

http://img219.imageshack.us/img219/1782/zbrushdetail.jpg


In ZMapper, I'm using pretty much the standard settings. I've made sure the resulting image is inversed, and I've set Display to tangent space normal maps. I then export the resulting map out, and import it into Maya, and I'm presented with a less-than desirable result:

http://img219.imageshack.us/img219/664/bumpdepth1.jpg


As you can see, the bolt detail is lost completely, and the only way I've found to reduce the harshness of the black lines that run along the edges is to reduce the bump depth to around 0.4, which surely I shouldn't have to do?

Maybe I'm missing something really elementary, but I'd appreciate any help anyone can offer. Are my settings in ZMapper incorrect, or is it a Maya problem?

Thanks in advance.
ambient-whisper
04-29-2009, 03:35 AM
try to invert green. or switch red and green, etc. theres a few things you could try. some apps read normal maps differently so you always need to do this between engines.
danshewan
04-29-2009, 09:20 AM
try to invert green. or switch red and green, etc. theres a few things you could try. some apps read normal maps differently so you always need to do this between engines.

Thanks, Martin. I tried both inverting the green and green & red in ZMapper before export, but the harsh black lines are still visible. I guess I'll try playing around with the settings, but thanks for the tip-off - at least I'm headed in the right direction.
ambient-whisper
04-29-2009, 08:00 PM
btw, in zmapper you can load specific profiles for the render engine and application you will be using.

try that.

if not, then how about you experiment with just the regular normal map creation tool and skip zmapper entirely. i know that one time i couldnt get zmapper to give me the result i was looking for no matter how hard i tried, but as soon as i used the regular normal map generation tool in zbrush the seams were gone.

theres soo many profiles that you never know which one will work. if only the engineers gave us the specs..
danshewan
04-29-2009, 08:52 PM
btw, in zmapper you can load specific profiles for the render engine and application you will be using.

try that.

if not, then how about you experiment with just the regular normal map creation tool and skip zmapper entirely. i know that one time i couldnt get zmapper to give me the result i was looking for no matter how hard i tried, but as soon as i used the regular normal map generation tool in zbrush the seams were gone.

Yeah, I tried using the built-in presets, but no dice. I have to confess I've only used ZMapper so far, though, so I'll give it a try. I'm not entirely convinced it's not a problem with my rig, as my video card's been misbehaving lately, but I'll give regular normal map generation a shot, too. Got a replacement card coming in the mail tomorrow, so maybe that'll help.

Who the hell knows sometimes? :D

Thanks again.
SpikeTheSpiker
05-03-2009, 11:18 PM
Hey I'm no expert in zBrush or Maya ( I haven't even used maya I have used max though)
I read somewhere that using symmetry on your objects will flip the normals on the other side, not sure if this will even help you or not but it might so I thought I should post it.
kelgy
05-04-2009, 03:09 PM
Not a normal map expert myself. I find that zmapper cant get really fine details. Usually I go to the highest subdivision level I can(out of usually 6 subdivisions), delete the lower ones, and then make a normal map from that. But usually fine details are rather blurred.

I am experimenting with the nvidia normal map filter for photoshop. You can convert a 16 bit displacement map into a normal map. You get much finer detail-and can overlay that onto the zmapped one, but I am getting some harsh results. Trying to find out how to make it more subtle.
ambient-whisper
05-05-2009, 10:58 AM
using normal mapper, in zbrush you can apply a sharpen, ( i think a smooth ), inflate, etc.

if you apply a tiny bit of inflate and sharpen then your creases will be tighter. also make sure that your using adaptive mode as well, otherwise youll get results that are smoothened. i havent used normal mapper in ages, so dont quote me, but every other baking option in zbrush, you want to use adaptive mode.
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