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Use the same AUV tile textures on Low/High Poly models

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#1

Using the Same Textures on a Low polygon, and High Polygon Model

Most likely useful for game models/textures

OK folks, I was working on a way to use the same texture on a low polygon model, that I created with a high polygon model using AUV tiles. I originally though of this idea because I am working on a Game portfolio, and I was looking to use high polygon geometry as a guide to paint the textures. This is easily done with a custom UV layout, but not so easily done using AUV Tiles. So I will cover the steps that it takes to achieve this effect.

This tutorial won’t work in the DEMO version of Zbrush. Sorry for the inconvenience. I recorded a zscript covering all of this, but it messed up around the time I started dividing and sculpting the model, thus rendering the zscript useless. So I decided to do the tutorial this way.

  1. Create your geometry. I used a simple Zsphere model in this tutorial, so you can follow along with what I did here.

  1. Make your low poly object to look like you want it too. In this case, I made a mushroom.

  1. Once you have your model made, take a look in the Texture menu in the Modify palate. This is what you should see.

  1. Export your low poly object, and save the file out as a .obj file.

  2. Now import the .obj file you just saved, and look again in the Texture menu in the Modify palate. This is what you will see.

a) This is how your UV's should be laid out if you choose to keep your AUV tile ratio set to 1. Both your original Zsphere model, and the .obj file will have the same AUV layout. You can check this by using UVmapper, which is a free UV editing program. I did this screenshot in Maya's UV editor though. If you want to create your own custom textures, you might want to look at Ken Brilliant's tutorial on using UVmapper. The .pdf file is located [here](http://www2.zbrushcentral.com/showcase/lessons/UVMapping.zip)

  1. DO NOT alter the UV layouts. Because your model still has the AUV tile layout that you made with the Zsphere model.

  2. Now you can divide your model, and create as much detail as you want for the model. In this case, this is how my final mushroom looked.

a) This is a screenshot of how the UV's look after you have divided the mesh to add more detail to your model. Notice how the UV's are still covering the same 0 to 1 aspect ratio as your original low poly .obj file.

  1. Now you can begin texturing your high poly model, using whatever tools you find necessary.

  2. This is how my mushroom looked after texturing it.

  1. This is the same texture applied to my original low poly .obj file, or Zsphere model.

  1. You can take this further into Photoshop or whatever program you use to edit textures in 2D, and alter this for Spec maps, Bump maps, etc…

  2. Another benefit of doing your models in this fashion, especially for games, is this give you the benefit of working on a large texture size, ie 4096 X 4096 initially, then if you need smaller texture sizes, all you need to do is scale it down to 512 X 512 or whatever you need it to be.

Have fun, and let me know if you still have questions. It’s not really that difficult once you get the idea.

Thanks.

PS: If you want to take a peak at what I made, here are the .ztl models, and the texture.

Low Poly Model

High Poly Model

Texture

#2

Hey Chad,

Thanks for this. Clearly explained and damned useful info. This is a link I will send to a friend of mine.

Well done. Sven

#3

Hi wchamlet¡¡
Awesome¡¡ Thanks alot for this very clear tutorial and it aplication¡¡
Thaks friend
Andreseloy
I did the exercise as you guide and work fine¡¡ Thanks¡¡

#4

AWESOME TUTORIAL!!!

#5

Hey, cool. I’m glad you guys like the technique. It’s a pretty simple idea, and nothing too hard to implement.

Now I just got to figure out why Maya still refuses to import certain AUV tiled objects. It’s driving me nutso!

And andreseloy, I hope this covered what you were wanting to know. If you want to know anything else, PM me or ask it here.

Thanks!

#6

As far as I know, AUV tiles are NOT acceptable UV layouts for games (at least the high performance ones), mainly because of all the extra vertex information in the UVs (each separate tile is 4 verts x each tile in the map = a LOT of extra verts). This type of texture would be unacceptable in a 3d game engine that relies on efficient sorting of all the data involved with a 3d object - textures, shaders, transforms, deformation etc. Also, unless all of your texture artists are using Zbrush or some sort of 3d paint program in the pipeline, the layout would be an absolute mess to work with in a 2d application like photoshop. It’s still the main work horse in a game pipeline as most game texture artists I know still prefer photoshop or painter for this type of work.

I’d love to be able to paint my textures using AUV tiling for our games. It would save me having to worry about doing UVs at all, but as I said, this type of layout would be unacceptable from a programmer’s standpoint(at least where i work). This is actually one area of the next version of ZB that I fear will be lacking still for game use. I’m hoping there will be more UV tools in the next version, but it doesn’t seem likely from what I’ve seen so far.

It’s a great technique and tutorial nonetheless! I just wish I could use it too.
:wink:

#7

One thing I’m thinking of is to buy a copy of Microwave for Lightwave and 1. Import the high poly model with AUV tiles into Lightwave and 2. Render the AUV textures onto a new low poly version of the high poly ZBrush model which has a more standard UV map. Has anyone had any success with this method?

Simesf

#8

Yup, Qwot, I understand where you are coming from. I think the AUV tile layout is one of the reasons why I’m having such a problem with importing my .obj into Maya. Too many UV vertices for the program to accurately process during import.

I don’t think the new Zbrush is going to fix that though. From what I heard it’s imperative for your UV borders to be straight, in order to extract normal and displacement maps, and that in turn is going to cause the same UV count problem you’ve mentioned before. Unless you are pretty clever in how you lay out your UV’s. But I still think AUVtiles is a better way to paint your textures, and I’m determined to figure out how to use them more efficiently.

What would be ideal, in this case, is to be able to switch from the AUV tiles to a custom made UV layout, that is more 2D editor, and UV vertex efficient. This would be good for two reasons, for one no or very little distortion on the texture, and for two it will give you the benefit of being able to manage your textures in a 2D environment as well. It seems that Lightwave has a feature to be able to do that, but I haven’t figured out a way to do it with Maya. I’m definitely going to look into it though.

Thanks for the feedback, and ideas.

Chad

EDIT:

I just looked up the price ofMicrowave for Lightwave, and it’s $300. That’s too much IMO. I’d much rather make my own custom UV layout. Now that I know what it is though, I’m positive I can’t do this in Maya. Bummer.

Back to the drawing board as they say.

#9

We’re using Microwave and LW as well over here. As far as I know the straight UV border is not required.

(edit: sorry, I think I misread your post as applying to LW, rather than within ZB)

Instead you have to tweak your smoothness settings for your surfaces in tandem with your edge creases on your mesh… it’s kindof a trial and error process, which isn’t ideal because you can’t view normal maps in real time in LW, but the results do come through with a little work.

This is where Zbrush would really come in handy if it could better handle custom uv mapping. You could do all your texture and normal map work right in ZB then. A few simple tools like a planar projection, normal-based relax, and some translation tools like move, rotate, scale, mirror would do the trick.

#10

If Zbrush had a UV editor, it would also need to merge UV’s, move and sew UV’s, and basically be able to select edges, UV’s, and Vertices. I think you’re talking about a complete rewrite of how Zbrush works! LOL

It would be nice to have though.

But if they start adding things like normal smoothing, UV editors, etc, etc… I can see the Zbrush program start to get bogged down like Maya, Lightwave, 3ds Max, etc… So for some reason I don’t see Zbrush getting a lot of the things a UV editor needs. At least not in 2.0.

#11

Only problem I see (not sure if anyones stated this already or not) is that the indentions that you have, should be inverted so they are bumps instead. Amanita muscaria’s have white protrusions on them, not indentions. Some are flatter than others but all are bumps.

Heres some images for you.
http://www.erowid.org/plants/amanitas/amanitas_images.shtml

#12

HAHA, that’s cool! I didn’t even think this was a real mushroom, I just made it up as I went along. I should have referenced it though, because the only mushroom that I know accurately is the Smurfs huts. Thanks for the tip, now I’ll know. :smiley:

I also wanted to point out that this technique isn’t merely for use in games. It can prove to be useful for large scenes when you need LOD for your models. Not everything needs bump maps, normal maps, etc… so this could work well if you wanted to, say paint a field of mushrooms and used particles to instance them. Especially if you are going for a hero shot, and you don’t need the hero model all the time.

PS: Thanks for the link! That’s some great reference!

#13

Interesting! Seems simple enough thanks I will give it a try. One question though, did you use texturemaster to texture your mushroom and if so, how did you get it to behave??

#14

Yes, I used Texture Master for the Textures. Tonight, I’ll post up a zscript on how I textured this, since I said I would do that many moons ago and I didn’t. I have the zscript of this being made, but halfway through it, the model is turned around weird and non of the sculpting/texturing turns out right. Maybe there is a fix for this that I am not aware of?

So without any unforeseen flub-ups, hopefully you will see a Zscript tonight.

Chad

#15

Hi wchamlet im very happy with this topic¡ I feel not only me, we are learning alot from you¡¡
I have a question: The texture you put in this thread:
1.-You retouch it or paint it in PSD? Each square?
2.-What other aplications once you have that texture?
Thanks friend…
Andreseloy

#16

OK, here is the texturing tutorial I promised awhile ago. You’ll have to download both of these files in order to get the Zscript to work.

Right click and save the files to disk:

Zscript

Model

To andreseloy:

  1. No, there isn’t a need to repaint something like this. If I wanted to alter this in a 2D editing program, I would make this a Black and White image to use as either a Bump, Specular, or Diffuse map.

  2. The only application I have that can use these types of texture maps is Maya. Zbrush handles these features without resorting to multiple texture maps.

#17

Your mushroom is coming along nicely.

Heres one I made, (more of a reference if you care to continue with this one) its the same variety of amanita, just in a younger state.

#18

Nice work Downwrdspiral!

I’m planning on making a whole bunch of “Real” shrooms as future ztools. But I’m looking for the best reference I can find now, so I can use some actual photographic elements in the textures. Actually, I’m not just gonna make shrooms. I’m going to make rocks, trees, grassy clumps, tree limbs, etc, etc.

The pic above was just a way to show how you can use different elements to make textures. Like I said before though, it’s not a real shroom, nor was I planning on making it a real shroom.

EDIT: Tons of pictures of plants, animals, and more here:

REFERENCE IMAGE ARCHIVE

#19

Nice Mushroom!! Have you ever tried makeing a mushroom out of the arrow3d tool?

#20

Yeah, you can make a mushroom out of pretty much anything. Although if you start out from Zbrush’s Primitive’s Ztools, you will loose the added benefit of having a low-polygonal model to save and use later. Although if you are working exclusively in Zbrush, this doesn’t really matter. But if you wanted to use this mushroom in another program, it’s always best to conserve your polygons, unless you are just focusing on the mushroom for your work.