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Normal and Displacement fail to generate their contents

ZBrush Usage Questions
#1

Hi Everyone!

Using ZBrush 3.1 on the PC

I thought I should sign up and see if anyone could tell me what I’m doing wrong. Here’s what I did.

Started a sculpture from a regular Sphere (making it a polymesh etc. first) carried on as normal, no problems whatsoever. Generated a UV map, checked it worked, again no problem whatsoever. Decided instead of subdividing the entire mesh each time I needed more detail. I’d try just doing a small part of it using masks, working on those bits, then a full divide and so on. Again, no problem. Checked the UV map, and again, no problem, no red appearing on them, everything was working just fine, better than fine.

Then came time to generate the normal and displacement maps. No matter what I tried, the normal map came out blue (the usual blue shade from a tangent normal map) with no details appearing on it. The displacement came out 50% gray, not a bit of detail on it.

Tried the regular ways to generate both, and also ZMapper and Multidisplacement. But neither maps ever contained anything. Remake the UV map, but again it just gave the same results.

UV map was just fine, everything appeared to be just fine. I’ve generated both maps many times before on other models, doing what I did this time, never had a problem. EXCEPT… This time was the first time I ever used masking to subdivide parts locally. That was the only thing I did this time around, that I’ve never done the other times.

So I’m wondering, does using local subdivision prevent these maps being generated? Somehow I’m thinking that’s not the case, as it would make a very useful feature, almost useless. So I’m guessing something else went wrong, but for the life of me I can’t work out what it could be. Because I’ve never had this issue before.

Could anybody help or offer some suggestions as to what it could be? I thought another thread I saw on here might have the answer (displacement maps having such faint details etc.) Yet I’ve happily made displacement maps of much finer details before today and been able to clearly see the shading on the alpha texture that’s generated. Same goes for the normal maps. I’m kinda lost at this point. I really would like to make better use of masking and local subdivision, but not if this is the result.

I no longer have the model. It wasn’t much use to me at that point.

Thanks Everybody

#2

Are you still at the highest level when you create your maps? That would explain what’s happening, since the maps are based on the differences between the current level and the highest level. If you’re already at the highest level, there are no differences to map.

If that’s not the issue for you, we’ll need more info about your steps and settings.

#3

Nope, was on the lowest setting. Nothing I did was unusual or advanced or any way different to how anyone would do it. The only thing I did differently was to mask an area, invert and subdivide it, clear the mask, work on it a bit, then subdivide the full model, continue working and repeated those steps a couple or so times.

I tried again after making this post, attempting to duplicate the same problem, and things seemed fine. But to me that doesn’t mean the issue is fixed, as whatever caused it to happen, ruined an entire model, making it unusable. Which isn’t a big deal with a simple five minute job, but will be a killer if it was to happen on something complex and detailed that’s taken days or weeks to do.

I just can’t for the life of me think what could have caused it, as I say, I’ve never had it happen before, never had any problems with displacement or normal map generation in ZBrush and am pretty sure it’s user error on my part (at least I’m hoping so, cause that can be fixed, a bug in the software is out of my hands), so hoping to work out what exactly I could have done to stop it working right. But as I did the exact same steps a second time and found it to be ok. I can’t work out why it hiccuped that one time.