ZBrushCentral

AUV's on decimated mesh - not working right

ZBrush Usage Questions
#1

Hi I have about a 5 million triangle Decimated mesh. I need to get some UV’s on this thing. I am trying whatever I can. Cranking up the Map Size and down the Border and hitting AUV but i just keep gettting a warning that it can’t be “optimal”

In the end no matter what I try the UVs are not what I expect. Its like a front face planer uv.

How can i get the usual UVs on this object? It can be tringle-for-triangle in any given order. I don’t care. Just so long as its within the 1-to-1 sheet and no overlapping, and some space in between would be good too.

I plan to render out an AO map.

thanks

#2

One thing i’m trying.

  1. Duplicate mesh
  2. Decimate it down really low
  3. Take it into Max and setup UVS
  4. Bring that back in. Divide it up
  5. Project to the original 5m triangle object.

The problem is that it will NOT project!!! why not?

Even if the main object is only like 200k. It will not project to the 5m object. It just hangs zbrush.

What could be the problem? Does project all not work well with decimated meshes?

thanks

#3

If you don’t necessary need an AUV map, you could try UVmaster, it work with decimated mesh.

You can try adding AUV before decimation and validate the option “keep UVs” in the decimation plugin.

Hope this could help.

#4

Adding AUVTiles before decimation won’t work.

The reason it’s not working even after decimation could be due to still having too many polygons for good AUVTiles mapping. (You’ll get that error message if the tiles will result in more space going to spaces between tiles than to the actual texture itself.)

Honestly, you’re going to have a hard time getting good results with any tiles mapping method. They just weren’t meant for triangles, and that’s what you have after using Decimation Master. As Steday said, you would be better off with UV Master. You can also use UV Master on level 1 of your original (pre-decimation) mesh and tell Decimation Master to keep the UV’s.

#5

I’m making a model for print. I heard I should hollow it out, but that was before I sculpted.

So what I did was cut a hole int he bottom. Then I decimated and exported that out. Then I created the inside and connected it with the bridge tool.

I brought that all back into Zbrush and cleaned it up a bit. But the problem is that the UV’s on this thing are not good. So I started to think of options. The best one i have so far is this.

  1. Take that final model (with the inside hollow). and Decimate it down really low. It still follows the form of the original model but is low enough to deal with.

  2. Bring it into 3dsmax and Quadify

  3. Fix the UVs and lay them out how you want. Inside stuff off of the sheet and the stuff that shows tiled out with some spacing.

  4. Export that obj and bring it into the original 5million poly object.

  5. Divide - Project All - Divide - Project All … Until i’m up into a printable range (5million triangles I guess is good)

Here is the catch. Each division is taking longer and longer to do. at the 1 million poly range i swear it took over a Day! And on the next division, which I was hoping would be my final at like 4 or 5 million. Zbrush just crunches away… 98$ CPU usage. Full memory usage… its been well over 24 hours and I just had to finally end-process.

It really shouldn’t take that long right? What could be the problem here. My machine is really nice and fast.

Thanks

#6

personally, i have yet to find a method that’s faster than what I do right now.

  • before decimation, drop down to level 1 and run GUV tiles
  • go back up to max level
  • preprocess with keep uvs and freeze borders turned on
  • decimate. tada
#7

Is it possible to know why you didn’t applied your UVs (all the ways you want) before decimating?
Applying UVs on 5 millions of triangles is a kind of intensive operation for all kind of software, except for basic unwrap (planar, spherical, cubic…) but splitting all these polygons to applies UVs won’t work for sure.
Same for UV Master, I’m pretty sure it won’t work. As mentionned in its documentation, the plugin is designed to work on “low” resolution meshes (approximately 500 000 maximum)

#8

Ok so i’m using UV master on a lot of these things now, which has been great.

But on one object I would like to control where the seams are.

So i followed this tutorial EXACTLY

http://www.youtube.com/watch?v=kOoOh5s8RE4

And it did NOT work out anything like he is showing.

The problem started when I went into painting. I painted the region I’d like to save and the region i’d like to have seams. The first thign I noticed is that his model has BOTH the blue and orange on it but mine will not do that. On the copy of the model I do not get both colors at the same time. When I switch modes it kills the previous mode.

When I do unwrap after painting in either mode it does not really respect what I have done. I clearly tried to preserve the front of my model but when I hit unrwrap its almost identical if not identical to as if I never painted anything at all.

Whats going on here? I’m following it EXACTLY and its hardly working out for me at all.