Polypaint -> "col>txt" GETS BLACK!

[KHAlexander]

I have polypainted part of the model. When I press “col>txt” it gets black and nothing shows!?!? (model gets totally black, nothing shows in the Texture “slot”)
ZBrush doesn’t seem to save the textures (+polypaint) when I close it so I would need an answer a.s.a.p. so I can export my texture.

Enable UV is on.
“Texture is off” (a new texture should be created regarding to a tutorial).
I’m on SubDiv 4 (highest +have tried lowest).
Character is the first tool over 8 other subtools.
I’ve tried to show and hide the other subtools.

Accidentally I pushed “unified skin” and a “3d” texture appeared???

Best!

[KHAlexander]

Okey…
I found some help on YouTube.

I went to the lowest Subdiv and pressed “AUVTiles”
I went to the highest Subdiv. Created a new texture, 1024x1024
I pressed “col>txr”
A “Texture” appears but… (see attached image)
tried to flip the texture but it didn’t work.

As you can see after the “making texture” it goes pixelerated on the model.

Best.

Attachments

[aurick]

The reason it went black was that your model had no UV’s.

Pressing AUVTiles assigned UV mapping, but it looks like your model has way too many polygons for a 1024 texture with AUVTiles.

What you need to do is assign a blank texture to your model that is a power of 2 in size (1024, 2048 or 4096) and has about as many pixels as your model has points at the highest level. For example, if your model has 4 million points then you’d go with a 2048x2048 texture.

After assigning the blank texture to your model, go to level 1 and press the AUVTiles or GUVTiles button. ZBrush will calculate the UV’s to best fit the currently assigned map. Then go back to the highest level and use the Col>Txr button.

Instead of using tiles mapping you can also import your own mapping. Go to level 1 and import a version of the model that has the mapping that you want. This will update the model. The key is that the point order must remain the same as what you started with. Otherwise the model will explode when you return to higher levels.

[KHAlexander]

Nope it just doesn’t do it. Tried to set texture to 4096 x 4096. Still gets messy. Model approximately 6,4 mil points.

Hid the other subtools and tried, negative.
Tried several different sizes to the texture, negative.

Is there any way, maybe, any “old” Uvs that messes it up?
I do not have any old model to get the “pointinfo” from either.

Sorry.

Best.

[aurick]

How many polygons does your model have at the lowest subdivision level?

What are the exact steps you’re following?

[KHAlexander]

[color=Wheat]Approximately 103.000 Polygons.

steps:

Setting the Subdiv to 1 (aprox 103.000 Polys)
Press “AUVTiles” / “GUVTiles” (tried both)
[color=Wheat] Setting the Subdiv to 4 (approx 6,6 mil Polys)
[color=Wheat] Creating a Texture 4096 x 4096
Pressing [i]“Col>Txr”

[/i]That’s it…

I can pm you with a link to the model if you want to check the model itself?
Maybe its something with it.

Best.

[aurick]

OK, first off your steps are wrong. When you press the AUVTiles or GUVTiles button, ZBrush calculates the mapping based on the current texture. If no texture is assigned, then it calculates based on a 1024x1024 map. So with the steps you outlined, your mapping is based on a 1024 map even though you’re ultimately creating a 4096 map.

Why is this a problem? Well think about it:

With AUVTiles, each polygon of your model gets one square on the texture. With a 103,000 polygon model, that means your texture map is broken down into 321 squares by 321 squares. So if the texture is calculated based on 1024 across then each square can be a maximum of 3 pixels across! But it gets worse: There’s a space of 4 pixels between each square. In short, with a model of 103,000 polygons pretty much the entire texture space in a 1K map is taken up by border and there’s really nothing left over for actual texture. The results are better with GUVTiles, but it’s still not going to be great. Mileage varies depending on the model’s topology.

Now with a 4K map you’re a little better off. You at least get 8x8 pixels per polygon (after compensating for the borders between them). But you’re only going to see this if you calculate the mapping for a 4096 map. If the mapping is calculated for a 1024 map (which is what you did), then all that really happens is the borders get made thicker without providing any appreciable improvement in available texture space. The borders are getting magnified along with everything else.

Here’s what you need to do:

1. Go to level 1
2. Create a 4096x4096 blank texture
3. Press AUVTiles or GUVTiles
4. Go back to the highest level
5. Transfer the color to the texture

By assigning the blank texture first, you tell ZBrush to calculate the map based on 4096x4096 instead of the default 1024x1024. This then gives you much more texture space.

I did try to point you in that direction with my first post:

After assigning the blank texture to your model, go to level 1 and press the AUVTiles or GUVTiles button. ZBrush will calculate the UV’s to best fit the currently assigned map. Then go back to the highest level and use the Col>Txr button.

Given the number of polys in your low level mesh, you’ll definitely get the best results from GUVTiles since that has fewer borders. However, I’d still recommend trying to reduce your poly count at level 1. You can possibly do this by using Tool>Geometry>Reconstruct Subdiv. Or you could use retopology. However you do it, the fewer the polygons there are at level 1 the less of your texture gets wasted on borders between UV’s.

[KHAlexander]

Thanks Aurick for the help.

I understand what you mean and see the error I made, :evil:, well trial and error
as they say when you are learning a new program, :).
Yes you wrote it in the first post :o just missed it I suppose. Was in the middle of it.

Thanks for a great support and response.
I’ll try these steps and hold my thumbs

Best.

[KHAlexander]

Ok, ran through it a few times. Didn’t work unfortunately. Tried to create a whole new texture + polypaint (screen with red areas), didn’t work.

I wonder if it can be the model itself? It’s my first so the workflow and so on could be messed up I mean?

Attached some screenshots as well. A strange artefact appeared when I
opened today, the red basic material bleeds through.
When I change to the white MATCAP I used from the beginning it disappears.

IMPORTANT Q!
IF I have made an error to UVs, can I reset it?
Does ZB keep the Uv history. I mean If I press GUV after AUv does it mess
up the UVs?
Same with the textures.
If you load a texture but is not happy with it and start the procedure all
over, does it just “overwrite” the earlier steps?

STEP 2
I loaded the Demohead and tried it. Followed the exact steps + as it shows
Pixologics videotutorial. Same error on the texture. (Its not as simple as the
video shows)

Attachments

[aurick]

Regarding the material, at some point you polypainted material onto your model. But you missed some spots. Since those spots have never had material polypainted onto them, they remain live and will use whatever the current material is. Simply turn on Draw>M, select the desired material, and press Color>Fill Object. This will fill the whole model with that material.

If you’re at level 1 and change the UV’s that update replaces any previous UV’s. The nice thing about polypaint is that it’s not affected by UV’s until you actually use the Col>Txr button. So you can change your UV’s as often as you want without losing any painting work.

For your final question, I’m kind of confused. Your screenshots are stating that you got rid of the artifacts. So where’s the problem?

[KHAlexander]

The problem remains regarding texturing. I tried with the demohead as well and
the same error occurred. It gets messed up. Thin lines and so on.

I’ve gone trough the steps a few times, very carefully to not miss anything.
Could it be some kind a driver incompatibility? (GFX Card)
Even tried some tricks I found elsewhere.

[aurick]

It’s not your graphics card. ZBrush doesn’t use it.

What version of ZBrush are you using? What is the exact version number that it gives in the upper left corner? Could you show examples that actually show the problem that you’re currently having? The screen shots that you show in your most recent post make it look like your problem was resolved. They look very clean, especially as compared to your original shots.

[KHAlexander]

I’m using 3.1.
The actual screenshots shows it all. The middle one. The one with the large
red brushstrokes. The texture just shows a “flat” surface with red lines.

The “demo/tutorial” in the videos, in your links shows an unwrapped texture
from the model. This is what I’m after. This makes it possible to tweak it in
Photoshop and refine its details. Then import it again.

Using the GUVTiles just makes a lot of small squares with red on it.
Using the AUVTiles makes as the middle image shows. Flat with red lines.

I don’t know if its me totally misunderstanding the ZBrush way to do it but
as I mentioned; in the video the texture comes out unwrapped and clean for post working.
Just as you work with ex. Bodypaint in C4D, the polys gets unwrapped based on the model.

Hope this info helps.

Attachments

[Kosher]

Sort of off topic but I still think it’s so awesome that ZBrush doesn’t even use the GPU. Nuts!

[Kerwin]

To do an unwrapped UV (versus using ZB’s tiling styles), you’ll need to export your level one to another program (such as Silo, Modo, C4D, etc.) and then UV your level 1 with their UV tools. Once you have your model cleanly UV’d, you can then reimport it into your model (the .ZTL file) by setting your model’s geometry to level and importing the UV’d .obj. As long as point count and order has not changed, ZB will make this UV’d model your new level1 and sub-divide the new UV’s. You will then get a texture map that can be later tweaked in photoshop.

You may be getting artifacts because your polygon distribution is a little strange in areas (I really can’t see this well in the pictures.) Re-topo’ing areas where the polygons are poorly organized may improve your map.

-K

[KHAlexander]

Thanks Kervin, I’ll try it. Im actually working in C4D so its perfect to try it out.

Thanks for the support.

Aurick
Kervin

Best.

[system]

Hey there, im having the exact same problem as you. it does the same thing as well however with displacment maps… find a solution yet?

[KHAlexander]

Kind of,
After I gave it UV:s it worked. But my goal was too get the “unwrapped”
effect of it. Like Bodypaint in Cinema4D.
Then KERWIN explained a bit. Have to check out the different procedures this weekend.

I still get the “strange” look of the textures. Just to get the work done I
decided to polypaint all of it instead.
Maybe I’ll create my own textures in C4D and PS.

Best.