Tips for sculpties with Zbrush

Hey ^.^ I've been using zbrush since version 3 came out last week, thought I'd share a few of the tips and tricks I’ve discovered for making sculpties, definitely can’t guaranteeing everything will work tho.

So far I've been able to use Zbrush3 to make OBJs, then import them to one of the other programs with the ability to export sculpt textures (maya and blender are good examples, theres bound to be more soon). This method seems to only work if you start from a model that's exactly 1024 polygons (to the best of my understanding, because 64 x 64 is 4096, this means a sculpt map can describe this many individual 'points', and since we're using 4-sided polygons for the most part, it seems a model exactly 1024 polygons will (almost always) translate into a sculpt map without any distortion.



Here’s a link to a base tool I've setup for zbrush and have had the most success with so-far, its just a tube-like cylinder missing the top and bottom vertices making it exactly 1024 polys (other shapes will work as a base too, this its just what's worked for me). It does mean you have to start from the same shape for every sculptie, but part of zbrush's fun is feeling like you're playing with a lump of clay ^.^

You’ll notice right away the base object has a hole on the top and bottom. This is unfortunately necessary, because we’re using a square map to define a 3d object, SL wants to finish of the top and bottom vertex itself (although not that well >.<. You can pinch and tweak the holes to make them smaller, as well as reposition them a bit. However, if you distort the holes on either end too much SL wont do a good job of capping the sculptie off, or it may not work at all.

Making textures to go onto sculpties is definitely tough, but here zbrush can help a bit here. I’ve found that making good textures for a sculpted prim seems to have more to do with how you make your model than how you create and export your texture. If you stretch the geometry or bunch it up (with Frame mode on, you’ll see the polygons either stretched out or squished), your texture will reflect this.

So, when making a model, its really important to try to even out the size of the polygons wherever possible. Zbrush has tools that can help with this, like pinch, magnify and tweak. Using smooth to drag from high density of polygons to a low density, and vise versa, helps even out the size of the polys.

Also, if you mainly edit your model by pushing and pulling geometry horizontal to the model’s top and bottom, you’ll get very little distortion when you texture it. If you push and pull a lot of geometry upwards and downwards, relative to the holes on the base model, you’ll get a ton of texture distortion.

One of the best ways to see how a regular texture will work on a sculpted object is to drop the sculpt texture on as the prims regular texture. The different color splotches in the sculpt map will line up over the spot they effect. Also, having a texture with a square grid on it will let you see how much your texture has been stretched & where you could possibly even out the geometry a bit more.

Here’s an example of a mushroom I made back on the beta grid. By keeping an eye on the polygons and making sure everything stays pretty even, when it came time to texture it wasn’t too difficult. Granted, there’s much more complex things to make than mushrooms, but the general techniques are pretty much the same.

example of a sculptie texture:

(just a thumnail, actual size was 512x512)

the end result:


One neat thing to try with zbrush3 is to explore the subtool feature, in the tools menu. It lets you have more than one sculpted object active at a time, so you can make a larger complex object by sculpting and lining up the individual parts as subtools, then export each part as an OBJ and make your sculpt maps. I've been able to make a few simple 2 and 3 prim objects using this method, with more complex objects it'll be a bit more interesting trying to re-assemble all the parts again in SL, but should still be possible

Hope this helps a few zbrush users out there. Good luck and happy sculpting ^.^

thanks for sharing. =)

as far as zbrush 3 is concerned, i'm having great success with the obj2sculpt.exe tool by Cindy Crabgrass (you can only sculpt certain 3d primitives of course). I just have to horizontally flip the bitmap in photoshop before uploading. it's easier than using yet another 3D app just to create a sculpt map..but I wonder if there's much difference between those produced by obj2sculpt.exe and Maya?

fab mushrooms Daryth!

Much thanks, Darth. I have been doing sculpties with zbrush and the converter by Cindy Crabgrass with pretty good but not consistant results. I made another try on a model that did not turn out well on the sculptie after reading your post and got a MUCH better sculptie.

Hi guys,

Is it possible with ZBrush to apply different (photograph) textures to different faces of the model *in* the geometry/3D window, and will it then automatically generate the texture/UV mapping that SL needs?? (<-- a rectangular texture, that has a spherical UV mapping, right?)

I'm still at a loss about how I should texture sculpties in an *easy* way ..

in my experiments - SL is encoding the poles on the sculpt map, and in order to get exact texturing across the poles, you have to work with the sphere, not a tube :/

I turned to the Wings exporter, which merely encodes vertex positions, including the vertex on each pole, and I'm getting a very exact uvspace in SL compared to the cylindrical UV method, which was messing up the texture across the poles. There's a huge difference, and if you want to texture all parts of the model, you have to go with a sphere.

Sometimes you have to bunch edgeloops near each other, if you want a more defined edge, with sculpts, it just means one has to get creative with textures. Zbrush helps to minimise distortions in textures via its 3d painting features. I am having excellent results by using a uvmapped sphere made to match the mapping in SL, and exporting the resulting shape in Wings.

I'm going to dig further into Zbrush and see if there's some way to export only vertex positions with it, because this is the best way to export a sculpt with exact UV information.

/8/20/183764/7.html#post1521794

is where I posted my OBJ sphere for Wings, that is already UV Mapped and can be imported and textured in Zbrush before export to Wings3d to use with the exporter by Omei Turnbull

And remember, make sure "flp" is checked in the export tab in Zbrush3 in order to not have a flipped model

Happy Zbrushing

Thanks so much Hypatia for the mesh to sculpt in zbrush and take into wings to export the sculpty map. I have been enjoying zbrush but going crazy trying to get my models into SL. This is working.

Sylvia, the trick is to literally move vertices from areas that don't need detail to the areas that do. The Pinch and Move tool are best for doing this.