It's important for me to know in relation to 3D printing, as I would have to think carefully about what I'd create in ZBrush and what I'd create in MoI. Is there a way to prevent the ribbing from happening, but perhaps more important is the question if this 'ribbed' model is of lower quality than the original MoI model, or if it just 'a visual thing'. When I try to increase the number of polygons by subdividing the model in ZBrush, it screws up the model and becomes unworkable (see attachment). (I attached a screenshot of the 'ribs' in 2 different colours and B&W.) When I open the same file directly in KeyShot without going through ZBrush, this 'ribbing' effect doesn't happen, and the surface is perfectly smooth. However, I've noticed that round surfaces are 'faceted' or are showing 'ribs' once opened in ZBrush. I'm planning on designing some things in MoI to have them 3D printed, and I can see how on occasion I would take a file from MoI into ZBrush for some further sculpting prior to sending it off for 3D printing. Hello all, I did some further testing with a computer running a KeyShot Pro version, and it indeed opens OBJ and STP files with ease. I'm really liking MoI and I'm looking forward to version 4. (While the subtool bit might not be of interest to you, I'm just mentioning it in case other ZBrush users browse the forum at some stage and have the same issue I had.) But when I turn on 'show polygroups', it neatly shows the different elements as I put them together in MoI, so then I just 'group split' all the polygroups which results in separate subtools, and thus allows me to assign materials as I wish once I send the model to KeyShot via the ZBrush Bridge. Note that when I open the MoI model in ZBrush, it shows up as a single subtool. It's a bit of a roundabout way of getting my MoI model into KeyShot, but it does work.

I did some more testing and digging and it turns out that the KeyShot version I have is 'KeyShot for ZBrush' and I can only open OBJ files if I open them in ZBrush first, and then send them to KeyShot via the 'ZBrush to KeyShot Bridge' (the regular, but more expensive, KeyShot version shouldn't have any issues opening OBJ files - my cheaper version is limited in what it can open).

Keyshot to zbrush