1.6 MB USDZ file is "too large to open in Quick Look"

Hey all,


I used usdzconvert to make a relatively simple obj with .jpg textures into a .USDZ file. The file is only 1.6 MB (per finder and my FTP server), but Quick Look on my iPad and iPhone are both claiming that "This file is too large to open in Quick Look".


Any idea if this is actually a file-size issue, or is there some other parameter I might be running into with my object?

Replies

The issue seems to have been my textures.


Out of the box, they were .tga files at 4096x4096. I converted them to .jpg for the USDZ process, but kept them at the same size.


After creating this thread, I scaled them to 50% and compressed the .jpg files to "medium" quality. This didn't bring my file size down too much (1.2 MB), but all of my devices are happy to display them now.

Nice catch, each of your 4096x4096 textures likely has a memory footprint of about 130 MB!

I've expereinced this exact issue as well.


Previously on multiple occations, I've successfully been able to preview usdz files on iPad/iPhone that have 4k textures. I am just not understanding why this one file I'm working with in particular seems to be "too large to open". It shows up perfectly in Xcode and Reality composer, though opening up the .usdz on the device, it shows the error message "This file its too large to open in Quick Look", even though its only 1.3 MB total.


Are there documented limitations somewhere to making these assets able to work properly on mobile devices?

Why is this issue happening *sometimes* and not others?

"This file its too large to open in Quick Look" isn't necessarily referring to the file size (1.3 MB in this case), but rather the in memory size required to display your model. If your model has lots of 4k textures like you say, then this in memory size will be quite large, Quick Look is likely making a determination that this in memory size is too large to display your model.

So what exactly is the in memory size limit? Is it a set/hardcoded value? How does Quick Look determine that?

There is no api contract on a particular size limit, the best thing that you can do is make your texture resolution as small as possible while maintaining model quality. Please file a bug report for better messaging using Feedback Assistant and post the number here for reference!

Additionally,


You can see more information about model optimization for AR Quick Look at https://developer.apple.com/videos/play/wwdc2018/603/?time=2166