Alpha view missing in IPR. Or is it?

[peter.fagerberg]

I have this bizarre behaviour in C4D (2024.1.0) running C4DtoA 4.6.6.1 [cd1215c9] – my Alpha view in the IPR only shows up if I make my IPR window smaller than the rendered image. I've never seen this before, and I think it's been that way since 4.6.6, but I'm not sure. The Alpha AOV exports just fine; it's just the IPR Alpha view that is strange (see enclosed video). All other AOVs display just fine in the IPR.

Is anyone else experiencing the same problem?

///Peter

Mac M1 Ultra | Ventura 13.5.2

[mat6R44J]

Same thing happening to me, except I was excited to see an update today in the hope that it would resolve it, but instead it actually got worse. Now the IPR not only fails to show an alpha, but I also have to reset it after doing almost anything in the scene. If I don't reset the IPR after every move I make in C4D, the screen renders black. It's actually unusable at the moment. Hoping for a fix soon!

I am also running C4DtoA 4.6.6.1. I'm using C4D 2024.1.0, and I'm on a Mac Studio M2 Ultra with Ventura 13.6.

[peter_horvath]

@peter.fagerberg I can reproduce it on Mac, but not on Windows. Will take a look and fix in the next release. Thanks for reporting.

@mat6R44J I have no other issues with 4.6.6.1, just the alpha glitch. By resetting the IPR, you mean you have to stop and restart? Is this started happening after updating from 4.6.6 to 4.6.6.1? There are no IPR related changes between those versions IIRC. 

[mat6R44J]

Thank you for the quick response! I've attached a screen recording of my additional problem in action. Yes, stopping and restarting the IPR works, but a slightly quicker method is to click on the IPR button to "force" a refresh. As you can see in the clip, I have to do this after any action taken in C4D to see an image in the IPR, otherwise it's black. Yes, as far as I can tell this did happen right after updating to 4.6.6.1. I've included the project as well, should you wish to test. Thanks again for all of your hard work and attention. 

[mat6R44J]

By the way, I've just confirmed that it happens on my Windows machine as well, exactly the same way it does in the clip I provided from my Mac. However, just as you mentioned in your response, the alpha problem does NOT happen on the Windows machine. A strange mix for sure. Could it be related to the cloners and field force, or dynamics?

[peter_horvath]

Thanks for the scene, I can reproduce the issue with it. Not sure yet what's going on. I'll keep you updated.

[peter_horvath]

The Dynamics Body tag triggers the issue. It's not related to the alpha issue or the recent IPR changes. Actually a bug in the instancer code, which sets the visibility of the instances incorrectly. Will be fixed in the next release.

[peter_horvath]

Not confirmed yet, but the alpha issue seems to me like a Cinema 4D bug. So it might take longer to fix it.

[mat6R44J]

Thanks for taking the time to look into it and confirm. I appreciate your skilled assistance! Looking forward to the next release. I suspected it related to dynamics in some way, but couldn't be sure. As for the alpha issue - we can hope for the best in the next C4D update.

[peter_horvath]

C4DtoA 4.6.6.2 supposed to fix both issues:

• Added a workaround for the disappearing alpha in the IPR. Still waiting for Maxon to confirm it's a bug in Cinema 4D or the plugin is doing something wrong, but this workaround should be good enough till then.
• Fixed the disappearing instances when the Dynamics Body tag is used.

[mat6R44J]

Thank you, I appreciate it!

[peter.fagerberg]

It certainly does - alpha is back! Thanks for the fix!! 😁