Zbrush and sharp edge

Jholen · Aug 2012

Hi to all. I'm new here.
I have a big problem with zbrush.
import a mesh with sharp edge, and apply subdivision (crtl+d), when I go back to my level one, the sharp edge are smoothed.
Here some pics:
Before smoothing

after smoothing

I know I can disable SMT modifier, but in this way the smoothing is pretty "ugly"

Any idea how prevent this?

Monophobe · Aug 2012

As far as I can tell you've maintained your edges when subdividing by adding supporting geo / edge loops. You'd probably be better defining your polygroups and using Crease.

Jholen · Aug 2012

Hi,
thanks for your advice
I using softimage, and softimage crease is not supported by brush.
I usually add support edges where needs in softimage but as you can see zbrush tends to move and smooth this edge I added, also the zbrush process for support edge is a bit... strange.

Monophobe · Aug 2012

Sorry, I mean use Crease in ZBrush. There's plenty of info online about this it, but hopefully this helps a bit.

Jholen · Aug 2012

Thanks a lot Monophobe, yes, I know this, when the hard surface is simple it work smooth, but when import hard surface with several details doing this in zbrush is a pain (for me)

Bek · Aug 2012

Would it be easier to add more edge loops before exporting to zbrush then? Add more than necessary so when you subdivide with smt the smoothing effect won't be as great. Then you won't have to polygroup / crease. Whatever works faster for you I guess.

Neox · Aug 2012

chamfered edges suck to sculpt on, as their density is so different from the rest of the asset. What i usually do is doublesmooth it in max, if i want the edges sharper i just pull up the iterations for the lower turbosmooth. Otherwise if you want to go the polygroup route, you can speed the process up by defining simple uv clusters and create polygroups automatically with uvs, so it splits your clusters into groups. It doesn#t matter if its nicely unwrapped it just needs different clusters, so its easy to do.

Jholen · Aug 2012

Would it be easier to add more edge loops before exporting to zbrush then? Add more than necessary so when you subdivide with smt the smoothing effect won't be as great. Then you won't have to polygroup / crease. Whatever works faster for you I guess.

Thanks Bek,
is what I do, as you see first image and look at the edge loop you can see there is applied some edge loops where I want sharp edge. When apply some levels (or only one) subdivision and turn back to level 1 (or export level one) zbrush rounding all relaxing the edge loops.

Neox, thanks for your advice, I will try. But why zbrush doing so? If I subdivide the some mesh in softimage (or blender or modo) there is no problem, when decrease it. Seems I ignored some parameters.

Internet Friend · Aug 2012

edit: hurf, someone already said this.

Ace-Angel · Aug 2012

1- Dynamesh your model at least once, at a high value.

2- Or Turbosmooth your model in your app by SG by a couple of times, import it in ZB, SD a couple of times, go back and reconstruct lower divisions as long as it's quads.

Bek · Aug 2012

Jholen wrote: »

But why zbrush doing so? If I subdivide the some mesh in softimage (or blender or modo) there is no problem, when decrease it. Seems I ignored some parameters.

When you smooth in modo using Sub-D it doesn't actually change the un-smoothed geometry. Zbrush subdivisions actually change the geometry all through the subD levels. Ie if you sculpt a huge blob on your mesh at the highest subD level, and then progress down in levels, you'll see the lower levels 'update' to support this new geo.

So that's why when you subdivide in zbrush and then come back down, your control loops have moved. You could get around this by just adding a crapload more support loops but as said before, the density difference makes them annoying to sculpt on.

Interesting method dustinbrown, I'll have to try that

Jholen · Aug 2012

Thanks to all

Bek, thanks for your informative contribution, but why Mudbox don't doing so? Can going up and down subdivision without my base mesh is deformed by subdivision itself.

Dustinbrown, your way seems work correctly. Thanks

Zbrush and sharp edge

Replies