Hi everyone!:)

I have been drooling over this gem of a program for quite some time now, but since I have always been the 2D illustration guy in my mind, I was hesitant. After playing with the trial version for a while, I enjoyed it so much, that I decided to pursue doing it for the fun of the process and hope that at some point I will have new tools for my workflow. :)

These days, I sculpt a lot using ZBrush and I render in Octane Standalone or Toolbag. Sometimes, I use renders as a base for painting, but I have come to appreciate the value of a good render by itself and a nice model behind it. I often use SubD methods with Zmodeler inside Zbrush to get really clean looking surfaces and forms and I really appreciate the crispness of how good geometry is rendered.

I am aware of the amazing shapes you can get by designing using nurbs vs usual modelling, but my main question is this- Is there any advantage in converting obj files to nurbs using MoI if the final result will have to be re-exported as obj or .fbx to be rendered? I compared two robot shoulderplates for example, one standard obj and the other one converted to nurbs and then exported again, and I could not see a visible difference in the render. What are the advantages of converting subD to nurb geometry? Maybe the answer to this would help me get a better grasp of the situation.

And another secondary question for any ZBrush+MoI users here. When I import fbx or obj models (exported from a nurb MoI model) into ZBrush, when I subdivide they never get very smooth. Am I doing something wrong? (I tick the weld vertices box in MoI export dialogue). I understand that this might be a pixologic peculiarity and the way ZBrush handles things.

Please feel free to suggest any workflow ideas! Being a 3D noob, I am surely missing a huge number of potential ways to take advantage of MoI for getting crisper and cleaner forms. And sorry if this post seems super confused, it's a combination of poor english and a very primitive understanding of 3D modeling :) But I do enjoy the process of playing with forms inside MoI, so there might be hope for me!

Andreas

Hi Andreas and welcome to the forum,

well, when creating shapes in MoI and bringing them into ZBrush there is no need to further subdivide,
imho, unless of course you would create a quad only low-res mesh in MoI. Usually one brings CAD
models into ZBrush for retopo and then further processing.

Regarding your second question, the subd2nurbs feature in MoI is very useful if you like to create
organic shapes, which are usually difficult to model with CAD Software. Once those organic shapes
are converted you can then treat them as NURBS shapes for further processing, like booleans,
trimming, detailing etc.

Hope this helps!

Regards
Stefan

Hi Stefan,

It's really nice to meet you! Thank you so much for taking the time to answer- It really helped a lot!

I just realized that scaling up my model inside MoI, created an exported obj of much higher resolution. I guess, my frustration with the faceted models coming from MoI was due to tiny original scale. I can see crisp shapes with smooth organic surfaces now even in Zbrush.

So, I could quickly concept an organic shape roughly within Zbrush, convert to nurbs modify and cutout shapes, vents, ports etc and then re-import and sculpt more organic surface details like damage and dents. Sounds yummy!

I wonder if I should tamper with the Scale factor under MoI settings in Import/Export to make sure I get good obj resolution or just scale up the stuff I do until I get sufficient quads on the preview during MoI obj. export... :))

Hi Andreas,

glad that it is working for you! The scaling should be no problem. The important
thing, you already figured out, is that you play with MoI's mesh export settings.

Paul Garboury once showed a video (on YouTube) how to use imported CAD
models for sculpting details on them. This is also very interesting, in case
ZModeler takes longer with modeling than with MoI. Unfortunately i can't give
you a link, because it been a while since i watched the video and i did not saved
the link. But this was also interesting, because he showed how to quickly auto
retopo a triangulated CAD mesh.

P.S. With ZBrush and MoI you have a superb modeling combo, imho! ;-)

Best regards
Stefan

Thank you Stefan!

I will definitely look into that Paul's video. I really like concepting in Zbrush, it is much more natural for me than starting from scratch in MoI. But comfort is not always for the better, so with time and getting used to shortcuts hopefully I will get a good flow in MoI too.

I want to try to import an obj in MoI and instead of converting it to nurbs, use it as a base/guide to draw curves on top of it. This could be extremely handy too to extract shapes, if possible.

I believe that is this one ;)
Minute 40

Hi Andreas,

re:
> What are the advantages of converting subD to nurb geometry?

It's so you can do a kind of hybrid modeling approach where you can build some element of your model that is organic or blobby shaped in a sub-d modeling program which are usually easier for those type of shapes but then bring it into MoI and do further work on it using things where NURBS modeling is good at like applying boolean cuts from 2D profile curves.

- Michael

Hey Pilou! Thank you for digging up the vid! Awesome info.

Hi Michael! I am starting to understand now. Thank you for taking the time to answer! I would also like to grab the chance and thank you specifically for what you have created, as MoI's design was one of the reasons I went deeper into modeling (me, a dude that paints). It's amazing how one man's passion and effort can have such unique outcome, resulting in a product that outweighs larger company titles on many aspects. Very inspiring.

MoI creates beautiful cuts and the converted subD is looks super smooth in render. Following Paul's method from Pilou's link (very roughly) I could remesh the obj that I exported from MoI. That allows sculpting nice damage detail but somehow destroys the smoothness of the original MoI export in curved areas (You can see at the upper right of the "issue" jpg). That is easily fixed by hand smoothing and it is worth the effort in my opinion. But I might just be missing something, I will have to go over the method again and play with settings. I really enjoy the combination of these two programs! ^^

Hi Andreas,

re:
> That allows sculpting nice damage detail but somehow destroys the smoothness of the original MoI export
> in curved areas (You can see at the upper right of the "issue" jpg). That is easily fixed by hand smoothing
> and it is worth the effort in my opinion. But I might just be missing something, I will have to go over the
> method again and play with settings

It could be that you're not getting vertex normals coming through but I also seem to remember that the ZBrush display mode by default likes to show polygons like that, maybe there is a display setting for that?

- Michael

Hi Michael!

You are absolutely correct, Zbrush occasionally displays a more faceted version of the model to improve performance during model rotation and does not do any smoothing between vertex normals according to what I have read.

The images I attached are renders in octane (with smoothing active in the material settings) and I suspect that this is an actual geometry issue due to Zremesher algorithm/settings I used. There are other settings with Zremesher that could potentially work to avoid this issue, but it has nothing to do with MoI's export which is perfect.

And please take everything I say with a grain of salt, I am new to the terminology and the programs and I do not want to appear like I understand more than I actually do. :)