ZBrushCentral

Answered: Confusion about a few things in ZB4...

ZBrush Usage Questions
#1

We’ve been enjoying the new features in ZB4, but have been hitting some snags too… (running ZB 4 on Windows 7 64-bit)

1- We sculpted some HD geometry prior to laying out UVs. We then laid out our UVs in an external app using the conventional method and brought that into ZB. When it came time to transfer the sculpting data, our HD geometry was ignored! The rest of the sculpt carried over, but not the HD geometry. Point order was maintained throughout. Only UVs were created. To summarize: we couldn’t make full use of HD Geo unless we had UVs on the model first. Did we do something wrong? Not jump through the right hoops in the right order? Or is this a known issue?

2-In Lightbox, we were stoked to see that we had a nice Alpha tab, and figured it meant we no longer had to load Alphas the long way. But when double-clicking on an Alpha in Lightbox, it loads into Spotlight instead of into our Alpha palette. Help?

3-Today I had a really weird one… I sculpted some detail on a layer, then baked it into the mesh at the highest level. I needed to delete part of my model so I dropped down to the lowest subd level, hid what I needed deleted, and ran “Delete Hidden”. When the operation was done, all my subdivision levels were intact as expected, but my highest level did NOT contain the sculpted data from my baked layer. This in spite of the fact that I had baked it and verified the result prior to deleting geo. This problem actually happened whether I baked the layers or not. The only solution I could come up with was to use GoZ to send my SubTool to modo, delete the geo I didn’t need, and send it back to ZB, which imported it and projected exactly what it needed to. I’m obviously missing some important truth about layers because the whole process was quite convoluted. I just don’t know why the “Delete Hidden” operation would also delete the baked effects of my layers. Help?

#2

I can help with the easy question in the middle! Hold down shift while double clicking on your alpha in Lightbox and it will go to your texture palette instead of spotlight. (sorry, the rest are way over my level of expertise :cry: )

#3

Thanks. That gets me part of the way there. That loads the alpha for the smooth brush, and then I have to pick it again from the alpha palette if I want to sculpt with it. Kinda backwards, but saves me from having to import it manually.

#4

Unless I’m doing something wrong here, yes. It seems to default to the smoothing brush which is strange. I’d prefer it just go to the palette and allow me to decide. This way requires an annoying squence of clicks to remove the alpha from the shift key and then reselect it from the palette for the main brush. Not much extra time in the course of history, but a distraction from the flow. Perhaps since we are using the shift key here, which is the key dedicated to smoothing, its designed that way on purpose, and there’s a different key combination to direct the alpha to the main brush. Hopefully someone will chime in here.

#5

1) Why are you importing and then transferring details? To update UV’s all you need to do is have the non-UV version of your model at level 1 and then import the UV’d version of your model over top of it. This will update the UV’s while leaving everything else as-is.

  1. Mask the highest level before you drop down and delete anything.
#6

I must have worded by initial explanation wrong. What you’re describing is exactly what we did, but our HD geo was ignored and in fact did not exist after the UV update.

Thanks! I’m not sure I would ever have guessed this though. Can you explain how this affects the process?

#7

About that alpha thing…check out this recent thread. Marcus explained a better way to accomplish this:
http://www.zbrushcentral.com/showthread.php?t=94233

#8

It’s not clear what you are doing - and therefore not clear why this is going wrong for you. Please give us an exact step by step so that we can understand the issue.

Thanks! I’m not sure I would ever have guessed this though. Can you explain how this affects the process?

With subdivision surfaces what you do on one layer will impact the other layers. If you delete geometry at the lowest level ZBrush has no way of knowing whether or not you want to keep the detail at the highest level. Masking simply makes your intention clear. :slight_smile:

#9

We’re following the standard method for bringing new UVs in, but just for accuracy’s sake, I’ll have our guy repeat the process and log each step. Basically: drop to lowest level, export OBJ, create UVs in other app, re-import OBJ with new UVs. Only… our HD geo would be gone in the final result, while the rest of our standard sculpting (on all levels) remained intact.

Two points about this:
- Not disagreeing with you or anything, but I don’t understand why ZB would think I don’t want to retain the detail of the highest level. But more importantly…
- Only the data from the baked layer was killed. The raw sculpting data from the highest level was retained. If I have to mask the entire mesh at the highest level, that’s fine, but it still doesn’t explain why only the data that was previously in a layer got deleted.

EDIT: About the HD Geo thing…One of our guys just did some more testing and he now thinks that while he was creating the UVs in an external app, he must have made some changes to the geo as well. If only UVs are changed, it works fine now. But I guess HD geo is dependent on identical point order, because if that changes, ZB will not reproject the HD data when we re-import the OBJ with the proper UVs.