ZBrushCentral

divide problem

ZBrush Usage Questions
#1

HI everyone,
Im quite new to zbrush (few intensive months of tutorials) and have maybe a very simple question I hope.
I have a base model imported as obj from max. and I noticed when I divide it a few times and go back to
the 1 level it is different then my original model. as if its smoother somehow… anyone knows why?
any idea will be appreciated
thanks
Elad

Attachments

pic4central.jpg

#2

When you divide a model, two things happen:

  1. Each polygon is divided into more polygons.
  2. The surface is smoothed, which also includes contraction of the mesh.

This happens with all programs that use Catmull-Clark subdivision. (Which is most all programs.)

Now the thing about ZBrush is that it has multi-resolution subdivision editing. When you change between levels, all changes made at the current level are translated to the other levels. So when you return to level 1, the contraction and smoothing that happened at the higher levels is translated to that level with the results that you show. This feature allows you to make changes at whatever level is most appropriate for those changes. For example, you can decide that the trunk needs to be longer, so you drop to level 1 where you can move just a few points. When you return to the highest level, any sculpting that you’ve already done at that level will be moved to fit the new shape. It’s a non-linear process, giving you more freedom to change your mind or try new things as you work.

However, there are times when you want level 1 to remain unchanged. For example, if you’re going to be exporting displacement maps from ZBrush. There are two very easy ways to handle this:

  1. Before dividing your model, press Morph Target>Store MT. Later, when you return to level 1 and want that original base mesh you simply Switch morph targets.
  2. If you didn’t store a morph target prior to dividing the model, you can do so when you return to level 1. Then immediately import the original version of your model, which will update level 1. The reason you store a morph target prior to doing this is so that you can Switch away from it if you need to go back to the higher levels. (See below.)

Just remember that if you intent to return to the higher levels for any reason you should Switch again or the new/original level 1 shape will be interpolated back across all levels. (Remember that this only happens when you change levels; not as your actively working at a particular level.)

#3

thank you aurick for the detailed answer ! I read it few times and will test this way…
Little before youve answerd I thought I found a bypass solution …with using the CAGE button when in level 1.
it looked as if the model came back to its exact original pose as seen in my pic. so I went ahead and exported it
back to Max then I found out I cant use it … since for some reason the vertices remained 1136 but the faces are no longer 1132 …but more faces were created somhow in the transition from ZB to Max and now its 1144.

so I cant copy from it the UVW info to my already rigged and animated model.
so all my texturing hours maybe lost…
all I want to know is How to transfer the unwrap info from one model to the next…
so the texture will fit …?

#4

Well… I found out the reason for the difference in polycount …is that I had some non quad polys and zbrush automaticlly
added edges (!)to them … I wish I knew how to ask ZB to not do it… is there a way ?