That's because they want you to use Float.valueOf(...) instead of new Float(...) for ... reasons. valueOf() has been added in 1.5, but jPCT is still being compiled to run with 1.4 to make it possible to run the software renderer on really old machines. If that's reasonable or not is another question, but that's how it is for now.
I don't think that they'll ever remove new Float(...), because it break lots and lots of old code for no reason other than some guy thinks that it's nicer this way. The same applies to finalize(). It's not advised to use it for your own horrifying purposes for at least a decade now, but they haven't provided any other way to clean up stuff before an instance gets garbage collected by the VM, in case the programmer didn't do it.

If you have something to share, I'll be happy to include it.

And I'm only using JDK 21 (I never go to bleeding edge purposely). Also: warning: [removal] finalize() in Object has been deprecated and marked for removal.

The good news: I made an OrthographicCamera class which works with minimal changes to AWTGLRenderer and World. I'll add it to SoftGLRenderer also. I'd be more than happy to share it with you if you added it to the official release.

This should work:

Object3D.mergeAll(new SimpleGlbLoader().loadGlbNoSkin(modelFile).toArray(new Object3D[1]))

Egon, could you possibly add that to version 1.33? I'm trying to mergeAll without looping but the line Object3D.mergeAll((Object3D[])new SimpleGlbLoader().loadGlbNoSkin(modelFile).toArray()) doesn't work. If I have to loop, we're back to very slow merging.

It works, thanks a lot. I'm glad jpct is back at form. Actually, my standalone GLB importer is nearly perfect now. I have a script for splitting animations inside Blender and exporting multiple clips straight into jpct, so it's better than at form.

Opps, I missed that. I've updated the download, please try again.

Exception in thread "main" java.lang.NoClassDefFoundError: com/threed/jpct/AWTJPCTCanvas$1
        at com.threed.jpct.AWTJPCTCanvas.init(AWTJPCTCanvas.java:53)
        at com.threed.jpct.AWTJPCTCanvas.<init>(AWTJPCTCanvas.java:38)
        at com.threed.jpct.AWTGLRenderer.init(AWTGLRenderer.java:73)
        at com.threed.jpct.FrameBuffer.enableRenderer(FrameBuffer.java:1154)
        at com.threed.jpct.FrameBuffer.enableGLCanvasRenderer(FrameBuffer.java:739)

Thanks very much. I'll let you know before I sleep.

I've compiled a new version that includes that change (actually, the code above isn't 100% correct, because it does some changes to the existing code that make no sense, but I've omitted those).

Can you try this one and see if it also fixes your issue: https://www.jpct.de/download/net/jpctapi_133.zip

It's software. I managed to recompile just the one class. And the fix worked!