We Talked With ZBrush Developer About ZBrush for iPad's Features

Following months of anticipation and dozens of teasers, Maxon has finally released ZBrush for iPad, an iOS-powered version of the beloved 3D sculpting application.

Announced back in October 2023, ZBrush for iPad includes many of the same tools and features as the desktop version, such as its collection of proprietary digital sculpting brushes and a highly customizable user interface. It also introduces lots of brand-new features, like the ability to customize the Apple Pencil's double-tap or Pencil Pro's squeeze gestures for actions like framing a mesh in the document or enabling PolyGroup. Moreover, the ZBrush for iPad comes with a free version, allowing everyone to experience many of the program's features without subscription.

To commemorate the release and learn more about the new version of the legendary software, I recently spoke to ZBrush's Product Development Manager Paul Gaboury, who kindly joined 80 Level to provide a behind-the-scenes look at ZBrush for iPad's development and tell us more about its features:

Would it be possible to use the desktop ZBrush license on the iPad or would it be required to purchase a new one?

Paul: Very excited to say that no, you won't need another license, any ZBrush subscription that you have will include ZBrush for the iPad. Some people might not be aware of that, but the subscription also includes Redshift CPU as well, so you actually are going to get three applications for one ZBrush subscription. The price has changed, though, and will be $399 annually.

The monthly plan will also feature ZBrush Desktop, ZBrush for iPad, and Redshift CPU and will cost $49.99/month. Maxon One will include ZBrush for iPad, so if you have either a ZBrush or Maxon One subscription, you'll get the iPad version from the get-go, and the price change won't take place until your renewal comes up. Moreover, ZBrush for iPad will have its own subscription pricing, which will be available via App Store.

Is there going to be a cloud for quick export and import of projects to and from the iPad?

Paul: We're not going to have a cloud at Maxon, but you will be able to use your iCloud and store your files there. There is also a big difference between iPads and PCs, an iPad is not like a desktop where you have multiple folders, multiple locations, multiple things, you literally can only have access to three locations on an iPad – your downloads folder, the folder they call On the iPad, and the iCloud. There's not really much else you could put stuff on an iPad.

You'll have access to all of those with ZBrush for iPad, and any file that you save, ZTL or ZProject, from the iPad is going to load automatically on the desktop just fine. You will need at least ZBrush 2025 on both ends though, so you cannot start on an iPad to then try and upload the files to ZBrush 2024 or lower, it won't open it. There's a lot that had to be changed under the hood for ZBrush to make the iPad also work, so there had to be file format changing as well. We are going to allow, however, for the iPad version to load old files.

We are also releasing a free version of ZBrush for iPad, which is very exciting because we strongly believe that allowing people to get into digital sculpting is really great for creativity, giving them an opportunity, "Here's a free version, just get in there and get going."

We already have that on the desktop side with ZBrushCoreMini, but the ZBrush for iPad free version is much more robust than the Mini version. I would say the ZBrush for iPad free version is a little bit closer to what ZBrushCore is on the desktop. It has feature limitations, but it's still ZBrush. One of the limitations will be that we don't allow exporting in the free version, but you will still be able to load your ZTLs and ZProjects, even from older versions, into the free version. But once you're in ZBrush for iPad, that is ZBrush 2025, and the only ZBrush that can open ZTLs and ZProjects is ZBrush 2025+.

Does the iPad version of ZBrush include a dedicated SDK for importing and exporting projects to and from other software outside of Maxon's ecosystem?

Paul: No, there's no SDK for that. Something would be different, especially concerning plug-ins, because you can't just take the plug-ins from the desktop and run them on iOS, it won't work, the code's got to be rewritten. We don't even have all of our plug-ins shipping because a lot of them have to be rewritten to work on iOS. So we're only shipping with a few of the plug-ins.

We started with some of the more popular ones to get going, like Transpose Master and Decimation Master. Going forward, we'll be working on the other plug-ins, trying to get the rest of the features that weren't able to make it into version 1.0 with each update.

But there is one thing that we did do – a new GoZ for the iPad specifically. The iOS version of ZBrush will come with an enhanced GoZ so you'll be able to one-click-send your file from the iPad to the desktop or vice versa. And it will be network-driven because that's the difference compared to the GoZ of today. Today, it's all in the same system, so it's more about just the system itself having all the files, but you can't have the desktop launch an iPad app and vice versa. But we made a really robust GoZ, which I'm really excited about. During the testing phase, I sent a 147 million polygon mesh from the iPad in under 45 seconds, and 30-45 million polygon meshes in under 10 seconds back and forth. So it can be really fast depending on your network speed.

ZBrush has hundreds of brushes and buttons that take up a lot of space on a computer screen, how was the software's UI adapted for the tablet without cutting anything?

Paul: The design of ZBrush for iPad went through a lot of iterations and design thoughts, with our main aim being to get over 25+ years of code, robustness, and customizability that a lot of users expect and get that same feeling on the iPad. But then, obviously, come the iPad-related challenges – smaller screen, smaller space, you've got touchability, and you have to make it quick and fast. So that's why we redid the UI, but we did the UI with the thought that we have to make sure there's also a linkage to the desktop because if someone starts with the iPad version and goes, "I love this, I want the desktop version," there has to be some kind of bridging similarity there.

That thought process was actually one of the most difficult things. Instead of just trying to make something from scratch for the iPad, I think it's maybe even a little bit more difficult when you've got something that already exists that users expect and know, especially those who have been using ZBrush for all these years. It was a challenge, but I think we executed it really well. I think you cannot feel the difference, no matter which one you're using – if you're on an iPad, it feels like ZBrush. But then we're also taking advantage of gestures, the pencil, and finger gesturing for certain things.

We also made an effort to make sure we involved the artists and beta testers very early in the process, asking them if we were going in the right direction and if we made the right decisions with the UI. We did change some things in the UI based on what the artists came up with while using it, so this was not necessarily 100% from our team – it was a collaboration, with some of the beta testers suggesting things. And there were even some things that someone would suggest that we thought were great ideas, but they would take a little more time to implement, so they're on our list of things to continue looking at.

And which feature was the most difficult to recreate on iOS?

Paul: Live Boolean took some time and understanding to make sure it works on the iPad. It wasn't too bad, but that one took some time to just get it up and running and do some testing. The plug-ins were also pretty difficult to get going. There was a lot of code change that needed to be done for all the plug-ins that we implemented, like Transpose Master and Decimation Master. GoZ took some time to really iron out and go through the testing. This one had a lot of quick iterations, really fast actually, like literally every 24 hours.

I would say in general, this was not something where you could just take the code and put it on the iPad – "We're done, yay!" Every feature had its challenges, all of them had things that we needed to change and tweak for them to work on the iPad. This was not a short-term project, so even when we announced it, we were already working on it. It's two-plus years' worth of work, and taking those 25 years and trying to squeeze them into this short period of time and get it to work the way we would want it to work and the way we feel that the users would want it to work on the iPad wasn't an easy task. There were some features that worked perfectly from the get-go and didn't require a lot of attention, but that was not the norm for sure.

How does ZBrush for iPad handle DynaMesh and retopology in general?

Paul: Handles it great. It works the exact same way as on the desktop; there is no difference between DynaMesh on the iPad and DynaMesh on the desktop. We will be restricting the resolution and some of the features for DynaMesh on the free version, so it's going to be a little bit like ZBrushCore, which also has a restriction where the resolution can only go to 1024. The subscription version, on the other hand, will have the full resolution of 4096.

There will be a couple of other smaller things for DynaMesh that are not present, but it works exactly the same. We also needed to try and maintain familiarity, so everything does work the same for ZBrush for iPad, and then the way it's going to work with the desktop – control-click and drag to remesh – it all works really well.

Sculptris Pro is also there, ZRemesher is there, Subdivision is also there, and if you've got an iPad that has at least one terabyte of hard drive or more with an M4 and M2 chip in it, you can get to around 90 million polygons per mesh. So it is the ZBrush that everyone is used to.

And what about Sculptris Pro, how well does it perform on the iPad?

Paul: Awesome, it's flawless. In fact, there are a couple of beta testers who live and breathe Sculptris Pro; they don't even use DynaMesh anymore. And none of them ever came back with feedback like, "Hey, this isn't working, this isn't right." For all of them, it felt like the desktop version.

One item that didn't make it into the first version of Sculptris Pro is the ability to click and drag to get the polygon size. It has to be recoded to make it work on iOS, so we weren't able to squeeze that in. But all the other Sculptris Pro features and things are there. You have individual brush control, global control – it's all there.

The difference in the way Sculptris Pro works on the iPad compared to how it works on the desktop is that it's device-driven, meaning however good of an iPad you have affects performance and can get slower or faster depending on your device. On my desktop, for example, I can get around five million polygons before I need to start hiding parts of it. Some people get around two or three million, but that's why we allowed Sculptris Pro to only display a portion of a model.

Could you tell us more about ZBrush for iPad's painting capabilities and PolyPaint?

Paul: We wanted to respect the fact that our users like to introduce PolyPaint early so they can look at the painted version of their models, not just the sculpts, so all the painting tools are still the same. The Paint brush is still there, and all the brushes will still work with poly painting. This is not going to be a stripped-down version.

There are, however, certain features that didn't make it into the first version, but obviously, the team is now figuring out how to add those features in future releases. The only thing that's not there right now is the ability to click and drag over the model to select a paint color – you have to open the UI, click on the color picker, and pick it. So that's the only thing that's really missing from PolyPaint. Some of the texturing tools also didn't make it into ZBrush for iPad 1.0; there is no texture map menu and SpotLight is also not there. But for the most part, the painting and texturing tools are the same as on the desktop.

Were there any tools and features that you had to cut entirely for the release, and if there were, do you plan to implement them going forward?

Paul: I would say the main features that are not going to be there in 1.0 are SpotLight, ZModeler, sculpting layers, and Surface Noise. Those are the four main features that aren't there. There are also some rendering features that didn't make it, like BPR Filters, and obviously, Redshift is not available on the iPad, but the aforementioned four are probably the main ones that people will miss.

Our plan going forward is to understand what exactly needs to be done to get them implemented on the iPad. For example, with ZModeler, you can't take what we've done on the desktop and put it on the iPad – the tablet is not big enough for the UI. Also, not all iPads have hover states; only M2s and up have that hover state ability, and ZModeler is completely driven by hover state. So there will need to be some changes in ZModeler to put it on the iPad.

The same goes for Surface Noise, SpotLight, and sculpting layers – their UI needs to be carefully evaluated and reviewed. That's part of the reason why some of these features aren't making it. We want to make sure we take the time to implement these features correctly because they will require some design and under-the-hood changes to work on the iPad, but we are looking to get them working.

I can tell you one feature that is not going to make it ever is the See-Through Mode – you just can't do that on the iPad. The tablet itself doesn't allow it, so there's no way for us to implement that feature.

Are there maybe any final words you'd like to share with our readers?

Paul: The thing I want to stress out is that developing ZBrush for iPad was no small task. The team has put a lot of sweat and tears into it, working crazy hours, weekends, 16-hour days just to get things going because they were so passionate and excited about what they were developing and making.

And it wasn't just the engineers, many people from other departments at Maxon were working their hardest, including marketing, QA testing, and designers, who were kicking out designs within hours. I was literally meeting with the designers daily just to make sure we were kicking out designs because they needed to stay in front of anything that was getting coded.

I'd also like to emphasize that there are humans behind this project and the work that they put into this was really unprecedented. As a person who has been developing ZBrush for 17 years, I've never seen so much passion and involvement across the board and multiple departments to get this going and keep the train moving forward by being involved.

Paul Gaboury, Product Development Manager

Interview conducted by Theodore McKenzie