iPhone app for alpha creation.


I am asking for opinions and advice.

I am writing an iPhone app, it’s purpose is to help create alpha maps for use in ZBrush. The idea is you are out somewhere, see a cool texture, get out your phone and open the app. Take a shot and it creates a colour, greyscale and high contrast depth map saved to your camera role. Preferences let you use a naming convention, adjust contrast to suit your needs, change export size, turn off certain exports etc. I want it to be very fast, very simple, and above all free.

I wonder if many people would use such a tool, and if so what your needs are?

I’m 80% done, I’ll be testing within the next 2 weeks depending upon my full-time work commitments, before releasing.

But yeah, just wondered if anyone would bother and if so what ideally they’d like it to have.

Thank you.


As a quick update, I wanted to share screen captures of the app in it’s current state, and the exports it currently achieves.

I can’t upload any images for some reason (invalid image error) so here is a link:

No responses, wondering if this app is pointless? I did say free, as in no charge, no ads, 100% free :wink:

Looks like a fun app to have, keep it up with the good work.
What about adding a function to share alphas with other “app” users? (like sketchclub app)


Could be interesting will the app allow you to set an export folder or will it be a case of messing about copying them from where ever itunes sticks them to the desired location if I end up having to mess around relocating files from my ipod to random folder from random folder to desired location I probably wouldn’t bother but if I can just run the app while my ipod is connected and it sees that files need copying and does it it would appeal more.
It could be good to have a feature for making tiling textures at a later date as the ipod cameras improve and removing shadows and highlights


The app will export to a specific folder, meaning when you sync with your computer the images will stay together. In the preferences you’ll be able to name both the folder and set the naming conventions for the images. Speaking of which, here are some test exports (half size and compressed for the forum).


This is great! I like that you are sticking to the kiss principle (Keep it simple stupid)
Keep going with this, I will download it for sure!

Now if someone would just get going on a .ztl viewer for iOS!

Quick update, the app is now working fully on the device. I’m testing memory use and stability, and tweaking the settings on the export of the images. Depending pun Apple the app should be on the store in 7-10 days.

For the Alpha creation, is it a simple greyscale conversion or a real depth extraction like you can see in CrazyBump ?


Both, you can turn it on or off to get a simple greyscale with bumped up contrast and/or an image which uses a Sobel operator. This is the export which needs the most work currently, tweaking it to get nice results. It may end up being a blend of the Sobel plus the Greyscale combined.

After the app goes up I’ll see how people find using it, and adult as required. But the app allows you to tweak the settings yourself to a degree also.


OK, then not a simple geyscale conversion, it’s good :slight_smile:

I’m so close to getting this finished, I have another freelance gig so it’s had to take a back seat. It’s basically done, I’m now just tweaking settings. I’m also going to be looking for testers, although I don’t know how to get the app to people before release so I need to look into that.

I found out today, due to a strange and never to be fixed bug with the iPhone 4 (not 4S, or iPad2 or iPad 3) the maximum export size on tweaked images in 1936x1936. Although that should be big enough for an alpha?


A quick update, it’s been a while since I could work on this due to my paying jobs, but the app is now finished. I’ll get some example files up for you ASAP along with some screen captures of the files used in ZBrush. The app is going through the submission process, if they accept first time around it should be with you in 3-4 days. If they don’t, well, that’s another story :slight_smile:

Due to memory limitations on the iPhone 4, the maximum file size is limited to 1800pixels square.

The app exports colour, simple greyscale conversion, and blended edge/depth detection maps with or without a circular alpha bleed. I already have things in my he’d I want to improve so I think there will be a V2, so please let me know of anything you want it to do.

1 thing I had to scrap because Apple won’t allow it is custom naming of the exported images. They do however sit in a app specific folder on your device, making it easy to keep them together when you import them onto your system.

Very quick test, it’s too hot to be inside doing this stuff. :slight_smile:

The image on the left is a simple greyscale conversion with contrast and sharpness tweaked, the image on the right is a ramp from the depth/edge detection and the greyscale, and the image I’m the middle is how it looks in ZBrush.

zAppa V1 is now on the App Store, go grab it for free:


V1.01 with a small bug fix is in review now. V1.02 with some enhancements will be going into review in about a week.

I have a list of things to improve, these will start to appear in 1.02. Grab it, test it, use it, let me know what you’d like changed/added/removed. This is a pet project, so I’ll keep working on it until it’s ready.


My main reason for creating zAppa was to make everything automated. See a cool texture, take the shot, forget about it and keep walking. Try it out and let me know what you’d like to see added.

Take care.

I tested your application just after seeing your tweet (I sent you DM from our official account, but no reply yet).

In my opinion, it really miss a progress bar or something which display what it is currently doing after taking a photo. You don’t really know what happen, you have to go to the setting then going back to the main screen to take a new photo. Then the idea is great, but it lacks some “ergonomic” :slight_smile:

Anyway, congratulation for having your app available, it’s always a hard work to do a project until the end!

I’ll tweet it on our official account as soon as the last bugs will be fixed :slight_smile:

Hi, thanks for replying.

Yes, the progress bar is coming in the next update. It was there to start with, but Apple wanted it removed because of the way I was polling the GPU for info. I’ve had to figure out another way to get at the state of processing. All the image processing happens in OpenGL to keep it fast, and also so I can write other filters. I’m looking at putting a normal map export in a future version for example.

Features I’m putting in are, apart from progress bar:

> grid to help aligning and keeping your maps in scale
> ability to not export the colour map
> landscape support
> using the volume control to take the shot
> full real time preview of the effects - this is my number 1 main upgrade priority.
> auto detect device to allow for the largest export available

Then in the next full number release I’ll hopefully add:

> rendering of effects onto existing photos in your library
> image editing, rotation, crop etc
> saving filter chains as favourites
> auto sync to a free online database of textures, free for all

EDIT: Just re-read your post, you don’t need to switch views to take another photo, once the processing is done the camera button will move back into view.

1 small update went live today, Apple seem slow at the moment but 1.02 is awaiting review currently. 1.02 adds a progress bar and fixes a small animation bug. I have collected a huge amount of maps from this thing, I’ll be sharing links to a collection of zip files shortly.

V1.03 will be a bigger release with some new export options and some overlays to aid in aligning and scaling.

Appreciate the app man, I have been keeping an eye on it. I want to give out a good try… not exactly sure what kind of alpha I want to capture but I am sure I will think of something good!