Support Quicklook for MacOS?

[NeighNeighNeigh]

Hello, this being so fast, I was wondering if you might consider making it work with Quicklook for MacOS… STEP viewing just a spacebar away would be extremely handy. Thanks for taking a moment to read this :)

[mkormendy]

This would be amazing.

[johnboiles]

I hooked this up today. It has full pan+orbit support (It's SceneKit under the hood). I'll need to polish a bit and get an Apple Developer membership to be able to distribute it though. Maybe I'll open source it but also put it on the app store to cover the Apple Developer membership cost.

[mkormendy]

@johnboiles To be somewhat future forward, might want to use RealityKit instead since SceneKit is deprecated now https://developer.apple.com/videos/play/wwdc2025/288/

[johnboiles]

Oh cool, thanks for pointing that out!

Edit: I tried out RealityKit/RealityView but I didn't like it for a few reasons:

• RealityView is SwiftUI but Quick Look Extensions have NSView/AppKit APIs so I had to use NSHostingView to bridge them and it was clunky
• I'm pretty sure the built-in .STL preview uses SceneKit and I want to match that rendering aesthetic (RealityKit has fancier lighting by default)
• I couldn't figure out how to enable pan+orbit, only one or the other via realityViewCameraControls
• In the video you linked they said they have no plans to hard-deprecate SceneKit

[johnboiles]

Anyone want to try it out? I've got it codesigned+notarized as a release build but I have not tried it on any machine other than my own. If you wouldn't mind screen recording the whole process of copying QuickLookStep.app to /Applications then running QuickLookStep.app so I can see when/how it prompts to add the Quick Look extensions that would be helpful. You should get two extensions added to Login Items & Extensions:

I'm not sure if you need to reboot or not to get Finder/QuickLook to start using the new extensions, so if it doesn't work, any Console.app logs for StepThumbnail and StepPreview would be helpful too!

QuickLookStepV1.zip

Here's what it looks like right now. There are thumbnails, previews, and a basic viewer app (since the extensions need to be bundled in a .app)

[prestonbrown]

Unfortunately, doesn't appear to be working for me. Can't find any logs for StepThumbnail or StepPreview in console. But it appears enabled? Restarted computer to make sure all finder processes would have picked it up.

[johnboiles]

Thanks for trying it! Strange that they show up in Settings but don't run. The one other person who tried it had a similar experience. Code signature looks correct to me:

codesign --verify --deep --strict --verbose=2 /Applications/QuickLookStep.app
--prepared:/Applications/QuickLookStep.app/Contents/PlugIns/StepThumbnail.appex
--prepared:/Applications/QuickLookStep.app/Contents/PlugIns/StepPreview.appex
--validated:/Applications/QuickLookStep.app/Contents/PlugIns/StepThumbnail.appex
--validated:/Applications/QuickLookStep.app/Contents/PlugIns/StepPreview.appex
/Applications/QuickLookStep.app: valid on disk
/Applications/QuickLookStep.app: satisfies its Designated Requirement

I need to find a fresh Mac to try to debug further.

[johnboiles]

Can you try running qlmanage -r and qlmanage -r cache to reload the generators list and reset the thumbnail disk cache?

Then run qlmanage -p yourstepfile.step (of course replacing yourstepfile.step with a real step file).

Edit: Let's also try:

pluginkit -mvvv -i johnboiles.QuickLookStep.StepThumbnail
pluginkit -mvvv -i johnboiles.QuickLookStep.StepPreview

And post the output (if any). Then run

pluginkit -e use -i johnboiles.QuickLookStep.StepPreview
pluginkit -e use -i johnboiles.QuickLookStep.StepThumbnail

[prestonbrown]

Sure thing. After resetting quicklookd and quicklook cache:

+    johnboiles.QuickLookStep.StepPreview(1.0)
                    Path = /Applications/QuickLookStep.app/Contents/PlugIns/StepPreview.appex
                    UUID = 9FEBDB63-B8B2-4117-8796-449A9AA97BB0
               Timestamp = 2025-07-24 15:11:01 +0000
                     SDK = com.apple.quicklook.preview
           Parent Bundle = /Applications/QuickLookStep.app
            Display Name = StepPreview
              Short Name = StepPreview
             Parent Name = QuickLookStep
                Platform = macOS

 (1 plug-in)

```pluginkit -mvv -i johnboiles.QuickLookStep.StepThumbnail
+    johnboiles.QuickLookStep.StepThumbnail(1.0)
                    Path = /Applications/QuickLookStep.app/Contents/PlugIns/StepThumbnail.appex
                    UUID = 4A52E595-7A6C-42D6-A9B1-E61B59C17218
               Timestamp = 2025-07-24 15:11:01 +0000
                     SDK = com.apple.quicklook.thumbnail
           Parent Bundle = /Applications/QuickLookStep.app
            Display Name = StepThumbnail
              Short Name = StepThumbnail
             Parent Name = QuickLookStep
                Platform = macOS

 (1 plug-in)```

[johnboiles]

Thank you!

This all looks correct. The + at the start indicates the user has elected to use the plug-in so that's correct. My only idea is to fully remove the plugins with plugin kit then add them back.

pluginkit -r /Applications/QuickLookStep.app/Contents/PlugIns/StepPreview.appex
pluginkit -r /Applications/QuickLookStep.app/Contents/PlugIns/StepThumbnail.appex
pluginkit -a /Applications/QuickLookStep.app/Contents/PlugIns/StepPreview.appex
pluginkit -a /Applications/QuickLookStep.app/Contents/PlugIns/StepThumbnail.appex
pluginkit -e use -i johnboiles.QuickLookStep.StepPreview
pluginkit -e use -i johnboiles.QuickLookStep.StepThumbnail

[prestonbrown]

Unfortunately, that did not work either. Preston

…

On Thu, Jul 24, 2025 at 1:16 PM John Boiles ***@***.***> wrote: *johnboiles* left a comment (Formlabs/foxtrot#12) <#12 (comment)> Thank you! This all looks correct. The + at the start indicates the user has elected to use the plug-in so that's correct. My only idea is to fully remove the plugins with plugin kit then add them back. pluginkit -r /Applications/QuickLookStep.app/Contents/PlugIns/StepPreview.appex pluginkit -r /Applications/QuickLookStep.app/Contents/PlugIns/StepThumbnail.appex pluginkit -a /Applications/QuickLookStep.app/Contents/PlugIns/StepPreview.appex pluginkit -a /Applications/QuickLookStep.app/Contents/PlugIns/StepThumbnail.appex pluginkit -e use -i johnboiles.QuickLookStep.StepPreview pluginkit -e use -i johnboiles.QuickLookStep.StepThumbnail — Reply to this email directly, view it on GitHub <#12 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/ABVTAX46SIQ4E5IOTWPDRQD3KEIGRAVCNFSM6AAAAAB4LER66CVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMZTCMJUGI2DCNZSHE> . You are receiving this because you commented.Message ID: ***@***.***>

[johnboiles]

Ok thanks for trying those. I think i'll need to find a fresh computer and try to repro.

[DerekK19]

I just installed on my M3 MacBook Air (Sequoia 15.5) I took notes and screenshots along the way. However like others, pressing the space bar in Finder doesn't bring up a quicklook and the preview is not displayed. I have a second machine, but it would be best to keep that one clean until I can figure out what the issue is (then I can try a full install on a clean machine).

I had a thought that maybe rust, cargo and python need to be installed (they are foxtrot pre-requisites), but since the app will view STEP files dropped on it, then it looks like the step viewing does work, just the extension parts are not.

I've checked in Console and there are three questionable messages:

Unexpected bundle class 16 declaring type a360.step
No extension found for \<private\>, reason: \<private\>
Sandbox: com.apple.quicklook.ThumbnailsAg(542) deny(1) file-read-xattr /Users/xxxxx/Library/Mobile Documents

(I replaced my username with xxxxx, and note the private tags in the second message, which I'm having trouble adding to the comment!)

These messages come up repeatedly when I select a step file in finder

[johnboiles]

Thank you for trying it! I'm glad at least that the failure is consistent.

I had a thought that maybe rust, cargo and python need to be installed

I'm pre-compiling Foxtrot as a universal (x86_64+arm64) binary lib for use in my application, so you shouldn't need any of the Foxtrot build dependencies on your machine. Making C-compatible libraries from Rust was surprisingly easy!

[rv0]

Was gonna try it, but I'm still on Sonoma (14.7.4), any reason why this can only work on Sequoia?