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How to work with real world scale if dynamesh doesn’t like it?

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#1

Hi everyone, I’m new to this forum and also I’m working on my (almost) very first sculpt in Zbrush, so I really need help. I think I’m doing something in the wrong way… I had kinda small character (17 cm instead of proper 170, that’s how I scaled the base mesh in Maya in the beginning, so it was in 1/10 scaling. I did it because the mentor in one course did the same). I was sculpting it in Zbrush, but stopped, decimated it, exported to Maya and resized my model from 17 cm to 170 cm (because I found out that it’s advised to work with real world size, not tiny characters), exported back to Zbrush. And now I can’t work with Dynamesh, because it creates really giant amount of polys. Even with 52 resolution it gives me 3 millions (actually, it gives minimum 3 millions no matter what I choose in resolution tab). I suppose I understand, that this is happening because of the model’s size - it’s too huge for Zbrush. But it’s 170 cm! :c It’s a proper, real world scale… What’s the point? I heard that it’s normal and even advised to work with real world sizes, but how to, huh, work with it, if Zbrush seems to not like it? Dynamesh, as I said, doesn’t work properly with such a big model (but, again, it’s not big, it’s real).

Hope for anyone’s help in it c:

#2

Hello @ImHereToStudy!

It’s not so much that Dynamesh doesn’t like them, as Dynamesh creates polygons at a fixed size determined by the rez slider. Objects that are smaller in the worldspace can only hold so many of these polygons, and larger meshes will receive more. I think Michael Pavlovich has a really good video illustrating this (and a lot of other helpful vids besides, if you’re new to ZBrush).

You can use the “Remesh by Decimation” function in Gizmo for finer control over the dyamesh process, which may let you hit a smaller target polycount.

However the best thing to do here is understand ZBrush’s import/export functions. The tool > export> Scale factor is a value that determines how much Zbrush will scale a mesh on export. If this number is set to zero prior to importing a tool, zbrush will auto-scale a mesh to work in the “sweet spot” of the Zbrush toolset, and will store the value of how much it needs to be scaled on export to restore it to the original size.

Many people import meshes with the default polymesh 3d star active. The default export scale factor of the star is zero, so any .obj imported will be scaled to the ideal size for internal Zbrush use (2 units). Upon import, that scale factor will be updated to the value needed to restore it to size. Give that a try, and be sure to understand the import/export functions of your target program as well.

#3

Hello

Thanks a lot for your answer, I’ve watched this video and also another one on #AskZbrush about scale parameter in Export tab to clarify everything. As I understand, when we import our model into Zbrush, it becomes small (ideal, I mean. These 2 units) and we actually work with a small model, but it will get its default size (as it was in a software from which we exported it in the beginning) during the export process because of this Scale parameter and the number what we calculated and entered. I just thought that if my model is big in (for example) Maya, it should be as big in Zbrush also.

Did I understand everything correctly?

#4

It sounds like you’re on the right track. ZBrush has a very deliberate worldspace and tools based on it–it’s what allows ZBrush to do some of the cool things it can do. But this means that you have to work within that ideal range for best results, and externally created meshes that must match scale in some other program may need to be scaled in order to achieve the best results. The import scaling should work automatically under most circumstances though.

If you don’t have to match scale in an external program, then none of this matters. Simply work freely, Unify meshes as needed to scale them to the “sweet spot” in Zbrush, then export. Scale as needed in external program.

Also check out Scale Master, if you ever need to work with more advanced scaling concerns and measurements.

#5

I’ve just done some test :smiley: I’ve created a 110 cm figure in Maya, exported it. In zbrush I imported this object on the star place, as usual. I’ve checked the Size parameter in Geometry tab - it’s 2 units by default as it should be. Than I’ve checked the Scale parameter in Export tab - it has 54,9 number. I do not even have to enter something or calculate! Then I’ve exported this model from Zbrush to Maya (just in order to stop my paranoia, heh) and got these beautiful 110 cm, not tiny object! Everything is automatic, it’s beautiful.
One case when I need to enter Export-Scale numbers myself is when I don’t have default size (for example, if I would create the whole model from zero in Zbrush without scaling it’s base mesh in Maya/Max/whenever else) but I want the model to match units of another software.
P.s. I’m sorry If sometimes it’s hard to understand what I’m writing, I’m not an English native speaker :smiley:

Thanks for your response, it was very important for me)