Zbrush Maps And Stuff

TheeStuK

Hiya! I could of SWORN exporting my model out of 3ds Max that I unwrapped everthing, but apparently not as when I generate a Normal Map, the whole map is straight blue, and when I "Check UV", the whole map is red. So my question is, did I waste 3 hours on my work, or is there any way to give my model a UV map so it will generate my Normal Map properly for me, or do I have to redo the whole damn thing?  Can I use UV Master and that UV for my model I'm working with? Thanks y'all

musashidan

If you spent 3 hours unwrapping it then surely you know whether or not you actually did!   you can either use the morph uv function in ZB to check if you have uvs. Or GoZ to Max and put an unwrap mod on.

musashidan

Also, in ZB are you generating the normal map from the base level to the highest level. If not then it might be baking from the high to high which effectively captures no data.

CharacterCarl

Have you done any modeling operations with ZModeler or merged your model with another SubTool? If so, it is possible that the UVs were deleted because of that.
You can always do a quick unwrap with UV Master though, to see if the problem indeed stems from the UVs or not. If you're working on a subdivided mesh hit "Work On Clone" from the UV Master menu. It will generate a mesh without subdivisions. Then "Unwrap" and "Copy" and "Paste" the UVs back onto your subdivided mesh before baking the normal map.

cryrid

I think the model needs to have UVs as a prerequisite to creating any maps inside zbrush, otherwise the options will be grayed out. The real question is what do your UVs actually look like, and what version of zbrush are you using? In older versions, zbrush would spit out pure red UV check maps and blank normal maps if you have UVs that touch the 0:1 UV borders or exceed them (like when mirroring any UVs). 4R7p3 is quite a bit better now, but it can still cause some issues. 

• If you're not beholden to your current UV layout and don't mind what UV Master spits out, then it should produce a map that will work fine inside of zbrush. 
• If you need a specific UV layout (ie: for straight edges) then you could either try exporting the lowest sub-d level (use a single polygroup or disable Tool: Export: Grp), fix the UVs externally, and then re-import the obj over your sculpt to update its UVs. The fix might be as simple as nudging some UVs away from the border, or scaling it down ever so slightly. 
• Mirrored UVs would be more of a problem, so you could just use a program like xNormal for the baking instead of zbrush (which is probably recommended anyway, at least for the normal maps).

TheeStuK

@musashidan , First, I absolutely loved your Warhammer Diorama you've made. I tried Morph UV, but for some reason it turned my model from 5mil polys, to a 23mil poly plain box? (I'll show you if I have to). If I use GoZ, do you mean bring the high poly model in and unwrap that, or the low poly? And yes, I am doing my highest SubD level.

@derrazputin , No, I've simply imported my mesh and got straight to work on it. And For some strange reason I don't have UV Master ;{

@cryrid , Here are my UV's https://gyazo.com/023d1de56c7ea377665e8f5152c45b64 and here is what I've made in ZBrush (this is my first zbrush thing ever, please don't laugh  ) https://gyazo.com/d829d72b6344fbfb3aa97c3c9e4c5882 . No, I don't need a specific layout, anything is fine. 
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When I opened my walls back up in Max, it didn't have the unwrap modifier on it, but I think I've exported it with the modifier on. Does this change anything, or I guess I really didn't export it with that modifier on? And can anybody perhaps give some other tips as to how to make mud walls like these (which is what I was trying to make above) https://gyazo.com/42bdaef650618d71df010e849448387b ? Thanks!