ZBrushCentral

UV mapping to existing OBJ failure of col>txt

ZBrush Usage Questions
#1

ZB3.1
XP x64 16GB
1TB disk
FaceGen model for testing. This loads correctly and displays the correct texture in all apps I have tried.

This problem was reported to support who asked that I place it here so they can see the files.

I have tried various tuts such as JC Cappelletti’s Texturing workflow but I cannot get the texture from the poly to the texture. I have read about others having the same problems.

Using JC Cappelletti’s system, after importing the original obj with the existing UV and doing col>txt (step 52), I get a white texture, turn off the texture and I see the poly paint.

To illustrate this I have created a flash video showing the problem and included the obj and texture I’m zProjecting. I put them both in a zip. Please can you tell me why it doesnt work.

Well I tried to upload it, but apparently its too big.

Get it here:
http://www.ftgate.com/tmp/zbrush_problem.zip

#2

There is another issue I have also seen that is apparent from the movie.
Why is it that sometimes when zProjecting there are areas that wont paint unless I move the referance point. You can see me do this in the video.
Sometimes there is just two patches, sometimes many. The same model loaded on two different occasions can have different behaviour.

I also forgot to say that the behaviour of both of these problems is also seen on a standad 32bit XP machine with 4GB. Different graphics cards in each machine.

#3

You’re overlooking a very simple step. You’re not actually creating a new texture. When you get to the point where you’ve imported your model and set the new texture size, you must also click the Texture>New button. Otherwise, no texture is created.

That’s not what’s causing this particular problem, though. In troubleshooting the problem, you’ve missed the most basic thing of all: Checking the UV’s. If you import the model and then immediately press Tool:small_orange_diamond:Texture:small_orange_diamond:Uv>Txr you’ll see your model get very colorful. Each color represents a different area on the UV’s. Ordinarily, this is very orderly. But with your model, it is all kinds of jumbled. This becomes even more apparent when you turn on the polyframe view. You’ll see that the color lines don’t even follow the poly lines. Instead, color edges cut haphazardly across polygons.

Horribly messed up UV’s like that prevent ZBrush from being able to successfully transfer color to the texture. You need to go back to your other app and rework the export settings so that the UV’s actually make sense when they’re exported. :slight_smile:

#4

Thanks for that. However, I am able to load the model and its original texture layer into XSI and other apps without any problems. I can load the texture map into ZBrush and it displays correctly.

Can you explain how the UV’s can be so messed up yet still display correctly in other apps and zBrush.

I have attached the original texture so you can see that it doesnt look that messed up to me.

andrea_skin_hi.jpg

#5

And the UV map from XSI which also looks ok to me.

texmap.jpg

#6

It looks like your UV’s are actually touching the edges of the UV space. The problem with that is that not all programs register the 0,0 point the same. With no padding around the edges of the space, any variation in registration of the 0,0 point will cause UV’s that are on the edge to be read as being on the opposite side of the mesh. This causes UV’s to be pulled across the texture and creates all sorts of headaches.

#7

HI aurick so how does one fit that? :confused:

#8

I think you could select all the points in the texture editor in XSI and scale them proportionally (using the shift key) inwards slightly. That way there would be a bit of room around the boundary points.

#9

The answer is different for every UV mapping program. I can’t help you there. :slight_smile:

#10

aurick are you saying you don’t use something like uvmapper or UVLayout Pro?

#11

If you scale it in XSI then it does work.

Its worrying though.

The obj loads correctly with the texure in XSI, Carara, Maya and Blender. The only app that it doesnt work with is zBrush. Sounds like a bug to me.

The really odd thing is that I can load the obj in XSI and then load the texture and it displays fine. It does txt>col fine. Its only broken for col>txt. Which is why I think its a bug.

I would have thought that fixing the handling of 0.0 so that its compatable with apps like XSI was something you should look at. If I have to texture 20 models I dont fancy having to rescale all the UV’s just to make zBrush happy.

#12

I’m stillamaze that were having this discussion at ZBrushCentral for Poser modelingI had gather more info here about Poser then at .smithmicro.com? Heeeey …when did they change the company name?!? :o

#13

I posted the correct solution to the problem here:
http://209.132.96.165/zbc/showthread.php?t=56352

#14

Thank MrFluffy!