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Polypainting : jagged edges, please help.

ZBrush Usage Questions
#1

Hi,

I’m new to ZBrush and have just bought it.
Until now I did my modeling and painting in modo 302 and all the rest in XSI.

Seeing all that great work on the forums created with ZBrush got me interested and convinced me this is a great tool.

But my first experiences with RGB-texture-painting (polypainting) are VERY dissapointing.
And RGB-texture-painting was my main reason of purchase.

I’ve searched the docs and the forums extensivley for two days now, and am sure that I’m doing everything correct, and I just can not get crisp sharp (color)painted lines or forms.
The edges are always jagged, even with Projection Master.

Workflow:

  • Model : modo
  • UVs : modo
  • OBJ : modo
  • ZBrush :
    – import OBJ (standard brush, freehand stroke, Alpha off, Texture off, Zadd and M and Zsub off, only Rgb on)
    – Color>FillObject
    – subdivide model to 7.809 million polys
    (31.237 million polys makes it run out of memory - XP64, 4 gigs Ram, Intel 45nano Quadcore, NVidia GeForce 9600 GT)
    – choose color and start painting with low Focal Size, and result = jagged
    – create texture 1024x1024 (even 8000x8000 doesn’t remedy)
    – Tool> Col>Txr
    – FlipV texture
    – export texture
  • Then in modo or XSI the painted cirkels or lines or whatever are as jagged as in ZBrush and I can’t find a way to clean that up besides doing my painting in modo or Paint Shop Pro.

Bummer IMO!

After having seen all that great work from ZBrush I still believe ZBrush is an awesome sculpting tool and my first sculpting trials are very promising but I simply can not believe the painting quality of ZBrush is that poor?

I hope someone can help me with this because I’ve read a post where someone had the same issues trying to create decent bumpmaps, and bumpmaps are what I was going to create mainly besides RGB-textures, resulting in ZBrush being pretty useless to me.
Should I have bought Photoshop instead?

Thanks, Dominiek.

#2

I’m new to this too and not sure what can be done.

I take it you understand that the polypaint works using each polygon as a pixel. So the more polygons you have, the more detail.

Sadly from my early experience, it can be an issue to get the detail you want on something like a whole body. As usually the polygons are smaller on the head, hands, and so on, compared to the arms and chest. So when you divide, and get to your limit, the head other areas are great, but the rest of the body still has too large of polygons to paint with. And since the other areas are so high, you can divide again.

I over came this in an annoying way. I had my final model ready, then I set polygroups for the head, arms, hands, feet and so on. Made sure the UVs were there before that (disable UVs deletes them, reimport if needed, but you may lose the polygroups). Then with subtools, split the model by groups. Now they are all separate pieces, but you can only paint on one at a time.

That’s not my plan. Now, with geometry panel, I crease the parts, then I divide the large body parts, arms, chest, once or twice to match the polygon size of the small body parts. Then I used a plug-in to merge the subtools back as one. They are still split, but it’s one tool again. And the UVs are still there and work right. Now, when I divide to my limit, and only being a fraction higher this time, I got the detail I wanted more evenly across the whole figure. And Color to Texture worked with the UVs as if it were still one.

End of part 1

#3

Part 2,

There’s a downside I found with polypainting. And that’s smooth UVs. You might as well not even worry about getting smooth uvs when transfering polypaint to texture.

There’s an issue, a bug I hope. When you divide a model, there’s a option next to the button to smooth the UVs as it divides. Seems simple. Nope, you just lost it. The moment you change your subdivision lower, then quickly switch back up, it’s gone. Or even if you avoid that, the day you quit and reload the tool, the smoothing is gone again. And if you already painted, no way to get it back without clever ideas. What’s even more annoying, when you generate a normal or displacement map, it has a smooth UV button that automatically smooths the uvs as it makes it, so why isn’t there a similar option when doing color to texture I ask.

There’s also another way of painting in Zbrush. Projection Master, the old way. This can be used with textures, and no need to worry about polygon count. Only limitation is you have to drop the model to the canvas, paint, pick it up, then rotate, then drop again. You get access to the all other other fancy brushes on the right doing this too. And if you have a texture already applied to the model, it transfers it right to the texture. One more thing.

With ZAppLink, you can have it load the dropped model into your favorite app, like Photoshop. The plug-in lets you save several angles at once, then when taken to photoshop, it renders just the diffuse (texture) then the shading on a separate layer set to darken or something to give you a preview as you paint in Photoshop. Then you take it back to zbrush. This works with polypaint too. And even with textures at 8000*8000, your painting will be limited by the canvas resolution and how close you zoom in to the model. There’s are guides here on the forum to get the best resolution and scale ratio to max out your texture detail.

end of part 2

#4

Part 3

Now if this seems to be an issue and not what you expected, and don’t have the money to get a 64bit Vista system with 8gigs of ram, there is one cheap alternative, but I’ve never messed with the program. It was recently renamed to 3D Coat.

It’s not suppose to be a Zbrush clone, but focuses a lot more on the painting part than sculpting. And it makes up for the sculpting with a huge array of painting tools with incredible photoshop like functions, even vector drawing I think.

Here’s a list of some of the features:
http://www.3d-coat.com/features.html

More examples: http://www.3d-coat.com/video_tutorial.html

The creator seems to listen to feature requests in their forum and a lot of updates, like this most recent one’s list (I recall the forum users asking for a way to paint right on the 2D texture like shown here as a new feature): http://www.3d-coat.com/news2_09.html Full list of updates: http://www.3d-coat.com/news_old.html

I’m considering it seeing how low the price is and great companion to Zbrush.

But, maybe others will have a better idea how to achieve your goals with Zbrush. I don’t even know how well 3D Coat works with textures. But I might be nice to see the low poly starting point of your mesh you are working with.

#5

Hello TimothyB and thanks for the extensive reply.

I’m really stunned: I thought that ZBrush would be a better painting app than modo, but in modo I can paint crisp lines on a simple smoothed cube (4 polys) and in ZBrush I can’t on a +7 million poly model !???

Smooth UV’s don’t seem much of an issue for me when I export the OBJ file from XSI with the “User Normals” checkbox checked.
They are an issue when I export the OBJ file from modo though.

Anyway, I guess I’ll have to focus on ZBrush’s strengths (sculpting) and not on its weaknesses and consider other painting alternatives like the one you have mentioned.
Will check that out or just stick to modo for painting.
I have been going through Meats Meyers intro to ZBrush and I’m really impressed with it, just not at all with it’s painting capacities.

Thank you and have fun, Dominiek.

#6

A picture of your issue would be helpful. If Im painting on a mesh with a high enough resolution, I dont experience this.

Some things to remember: 1) If you're going by the in-zbrush display, Zbrush doesnt antialias anything except at rendertime and in "half size" mode. All lines will be "jaggy". Click on the "AA half size" button on the upper right of your canvas frame to preview lines with AA. 2)Make sure you arent zoomed in too far on the canvas. Zooming in too far with the 2d zoom will pixelate the image just like in photoshop. If you are basing your observation on a texture exported from ZB: 1) Use poly paint on a high rez object, then generate a texture from polypaint. 2) If creating a texture, make sure it is large enough to support the object (1024 sounds too small for an 8mil poly object) 3) Make sure your UV's are laid out in such a manner that the eventual texture is well utilized (not too few pixels trying to cover too much detail). Zb tile mapping can be good or bad for this depending on the object...if youve got a lot of hidden polys gobbling up image pixels, it would be better to lay the texture UVs out more deliberately to utilize more of the texture image where needed. 4)If you are trying to get crisp lines, make sure to use a hard edged brush, or a brush with no falloff.

5)Some objects with complex geometry can be hard to subdivide smoothly for polypaint. If you can’t divide high enough for satisfactory results, bypass polypaint and simply apply a texture (make one about 2048 square) and paint directly on the texture with projection master…your lines will be fine.

#7

Hi Bingo_Jackson,

The problem is that the complete model can not be subdivided enough to get crisp lines when rendered. It’s not a matter of them looking jagged in the viewport, but in the renders in modo or XSI.
The UVs are covering complete UV space and even with a texture size of 8000x8000 the lines are still jagged.

I’ve tried Projection Master and then the lines look crisp but are also jagged in the renders.

I’m trying out 3dcoat right now and after a few minutes I know this will become the painting app of my choice as it does without hassle what I expect from a painting app.
And with crisp lines at low texture resolution.
And only for 120 dollars!!!

I will use ZBrush only for sculpting displacement and retopo and its other great functionalities.

Thanks for trying to help.

#8

And after comparing 3dcoat to modo I guess I won’t buy 3dcoat after all because modo still does the best job in painting crisp lines and dots onto the geometry.

I think the only way to improve the “crispyness” of modo is to paint in a 2d package.

Have fun, Dominiek.

#9

Could you post examples of what you are testing with those two apps? Only if you have something on hand. I’m just not sure by what you mean crisp. Are things looking pixelated, or just soft, are these thin lines, or edges?

#10

I’m not saying Zbrush is as good of a 3d painter as a dedicated 3d paint program…its not. It has a number of limitations…this just isn’t one of them from my experience. Many people use it quite successfully for their painting needs.

I just spent 5 minutes in Zbrush and rendered these in XSI, with the AA slider on render region turned up to the second notch from the top. The one on the top is painted on to a 2048 texture applied to an 8000 poly sphere with projection master. I did this fast, but could have done even crisper, more precise mechanical lines in photoshop and Zapp link, but I was in a hurry. The bottom is derived directly from polypaint with an 8 million poly sphere. [[attach=95143]xsirenders.jpg[/attach]]![xsirenders.jpg|445x720](upload://6LUgwbM9YlpR3yVp9ie1nXDEmMj.jpeg) Granted, polypaint tends to be better suited for more naturalistic soft organic painting. Precise lines and hard shapes are better applied with PM and Zapp Link ( you do know you can paint directly onto your model in photoshop with Zbrush and ZaPP link, right?). Polypaint is simply a more convenient functionality upgrade from the last version of ZB, which was all PM, but it doesnt work well for everything. There are any number of things that could be going wrong in your technique in both Zbrush OR XSI that could be causing your issue, but we can't get any idea about that without getting a look at what you're seeing, your mesh, and how your UVs are laid out.
#11

Thanks for the info.

@ Bingo_ackson:
You’re right, I guess for more organic texturing ZBrush will be great : see the galleries for evidence of that.
But for more crisp outlines even your 8 million polysphere shows jaggedness and certainly will in a closeup.
Your image is a perfect illustration of what I am trying to avoid.
The best examples of it you get when your basemodel has low polycount and when you turn on sds (TAB-key in modo / + and - keys in XSI) => then the rgb texture also gets distorted on top of the jaggedness, which does not happen when you paint on a low polycount model directly in modo.
(The smoothing problem however can be avoided when turning on “User Normals” in the OBJ-exporter from XSI.)

@ TimothyB : sorry : I just uninstalled the trial version of 3dcoat.
My first impression was very good, and the testimonials about it from several modelers with good repetution that you can read when following the links on the 3dcoat website “prove” hat it is worth its money, but I find that modo does what I want for painting crisp lines and dots so I will stick with modo for those textures and can always paint the more organic textures in ZBrush making use of all of its great brushes.

So the best way foreward is probably to use the best of both modo and ZBrush.

Thanks …

#12

I honestly don’t know what you’re talking about.

[[attach=95153]BIGbluetextrender.jpg[/attach]]![BIGbluetextrender.jpg|878x612](upload://c9DMti1D3AHzcjMI5Vv6yIGsgEp.jpeg)

Two people have tried to explain to you now that PM is independent of polycount. It paints directly onto an applied texture. It works on the relationship of texture size to display size, in the tradional sense. It is a little fidgety, and not as direct as you might be used to in some other 3d painting apps, and for that reason alone you may wish to use another tool that youre more used to or works in a more direct manner. Polypainting is something different in Zbrush, with pros (like being texture and UV independent, as well as direct and intuitive), and cons (like being mesh resolution and topology dependent, which makes it suited for some things more than others.).

But ZB is not inherently incapable of generating the same lines and pixels any other 2d or 3d app is, though some brushes and settings might be problematic.

In the first image I showed you, the top sphere used PM and there are no discernible jaggies, save for the limitations of the low res jpeg. In the bottom image, I think you may be confusing aliased “jaggies” with soft brush falloff. The unevenness of some of the contours of the long freehand stroke are due to dab spacing issues, and my own uneven hand.

Of course any raster image is going to become pixelated if you zoom in farther than its large enough to support.

I have no idea what your issue is. There could be any number of things on either the ZB or XSI side factoring in. If you are rendering with Anti aliasing turned up in XSI and seeing actual jaggies(within reasonable expectations), at some level you are either asking a texture image to display larger than it has detail for, or have not gotten enough detail into the texture for a number of possible reasons. If you are seeing “fuzzy” or overly soft strokes, that could simply be an issue of brush quality, and you can always bring Zapp link into the mix to put every tool in Photoshop or Painter at your disposal within Zbrush.

But its impossible to say anything, because you still refuse to show us anything that might let us help you. You seem determined to jump to conclusions about a tool with which you are not experienced, compared to one you are used to. Use whatever tool you want, but don’t waste the time of people who you asked for help, who use this tool for mesh painting to great effect every day.

#13

It seems to me that you’re missing a fundamental aspect of polypainting:

You need to have close to a 1-to-1 ratio between the number of polys in the model and the number of pixels in the texture.

The reason I say this is that you’re taking an almost 8 million poly model and trying to create textures that are 1024 in size, and also 8000 in size. Neither of those will give good results. In the first case, your texture is too small to hold all the polypainted details, and some detail will be lost. In the latter case, the texture is too big for the details and it’s no different from taking a texture and enlarging it in Photoshop. The texture may be larger, but the edges certainly won’t be crisp.

A 1024 texture has a maximum of 1 million pixels.
A 2048 texture has a maximum of 4 million.
A 4096 texture has a maximum of 16 million.
A 8192 texture has a maximum of 64 million.

I say maximum because almost all textures have wasted space. Sometimes a lot of it.

So if your model has 8 million polygons, then you probably want to use the 4096 texture size. The 2048 size would lose about half the details you’re painting. The useable space of a 4096 texture is about 25% larger than your model’s poly count, so you’ll get the best results.

Regardless, all textures are going to pixelate in your renders if you zoom in far enough. The moment you zoom in far enough on the model that the texture’s pixels have to be rendered as more than 1 on-screen pixel, you’re going to get jagged effects. This is why multiple textures are needed when you’re going to be zooming in really close to a model. There’s just no way that a single texture can hold enough detail to zoom in all the way. Especially with a figure model.

So far, I’ve been talking about polypainting. Painting with Projection Master is a different beast. With that you don’t need to worry about number of polygons because you’re painting directly on the model. But painting on your textures with PM you need to think about something else: pixol to pixel ratio. Every pixol you paint on the canvas while the model is dropped should correspond with one (and only one) pixel of the texture once the model’s picked up again. Anything else will result in a poor quality transfer. You can learn more about this in my tutorial here: http://www.zbrushcentral.com/zbc/showthread.php?t=27680

#14

Bingo_Jackson : But its impossible to say anything, because you still refuse to show us anything that might let us help you. You seem determined to jump to conclusions about a tool with which you are not experienced, compared to one you are used to. Use whatever tool you want, but don’t waste the time of people who you asked for help, who use this tool for mesh painting to great effect every day.
I appologize for that because that was and is not my intention.
The reason that I did not post any pics myself was not because of refusal from my part but because I kept on doing test after test trying to get it right and because my website is down at the moment, I would have had to create an account at Imageshack or something and did not want to waste more time with that.
I guess I should have.
And now that I am writing this, I see that I can directly upload pics here on the forum without having to create an account on Imageshack, so stupid me, but I’m used to the Luxology forum where you can not do that : on the Luxology forum you have to host your images elsewhere.

But you are right however about jumping to conclusions too soon : I’ve spent the afternoon trying to paint crisp lines in Paint Shop Pro and I did also not succed at that, so I guess also aurick is right when he says that I am missing a fundamental aspect of polypainting.

The second image Bingo_jackson is showing is what I am looking for, but my own tests with PM did not achieve such a good good result.
So I guess I’ll have to do more tests and tuts like aurick suggests to get the experience needed and gain more knowledge about 2d painting in general and 3d painting in specific.

Again : sorry if you feel that you are wasting your time but in fact you’ve been of great help to me Bingo_Jackson.
Also thank you TimothyB and aurick. :+1: .