Black Frames in Animation

[mrittman]

I am rendering an animation that is about 200 frames in length. It's basically a simple camera move as a bullet is being loaded into a chamber. There are 3 frames of my animation that render completely black. I am rendering 25 passes, and at pass 5 is when it goes black... very strange! I have attached a screen grab of the Corona VFB and I right-clicked to show pixel info. I also attached a render of the very next frame, and as you can see, it renders fine. I am rendering at 864x486 size at 72 dpi. Denoising is set to 0.4. I have tried disabling this, but it doesn't seem to have any affect. I should note that rendering in the viewport doesn't have the issue of the black frame...just rendering to the VFB.

Also, I noticed when I switch the GI solver to Path tracing, it no longer renders the black frames. I would attach a scene file, but I've put a lot of work into this and prefer not to make it public :D

Corona Sep 5 2017 on macOS Sierra (10.12.6).
Cinema 4D version 18.048
Intel Core i7-3720QM CPU @ 2.60GHz

[houska]

I would attach a scene file, but I've put a lot of work into this and prefer not to make it public :D

Hi, Matt and thanks for the report. I'm personally not aware of this bug yet, but maybe the other guys will know, whether we encountered it yet.

In any case, I just wanted to remind you that you can always use the new private scene uploader, which lets you upload scenes or other stuff for Corona staff eyes only. You have our word that we will never share your scene with anyone without your consent and that we will only use it for debug purposes.

Of course, we will understand that you still might prefer to keep the scene private only to yourself.

[mrittman]

Hey Houska,

I went ahead and uploaded my scene file using the private uploader :) The file name is black-frames.zip

I have it set to the frame that goes black (298). I can't remember the other frames that were bad! If you render the entire animation however, you'll see there are 3 frames that are bad. It usually goes black during pass 5. Thanks so much for looking into this!

Matt

[houska]

So it should be enough to render the frame 298 as a single frame, right? Or do I have to try out the whole animation?

[mrittman]

Yep, you can just render the single frame :)

[houska]

So it does not happen in the newest build (the one with IR). I'd suggest to use pathtracing as a fallback for now and then use the IR daily build when it's stable enough...

[mrittman]

Yeah I noticed it didn't do it with the version with IR either. However, the version with IR seemed to render the lights with a higher intensity, so I didn't want to switch to it quite yet. I'll wait till it's more stable :D

[houska]

Yeah I noticed it didn't do it with the version with IR either. However, the version with IR seemed to render the lights with a higher intensity, so I didn't want to switch to it quite yet. I'll wait till it's more stable :D

That's a wise choice, if it's a commercial project :-)

[houska]

Hi Matt!

What's the status of this one? Have you encountered any black frames recently?

[mrittman]

Hey Houska!

I will try and test this tonight when I get home! I haven't done any crazy rendering since I finished this project, but I can definitely open it back up with the current version of Corona and see if this is still occurring.

Thanks!
Matt

[houska]

That will be great Matt. Thank you!

[mrittman]

Houska,

Okay so I re-rendered this at the same frame that would have produced a black frame. With the most current version of Corona, it works fine now. I did not render all 250 frames of animation, so I can’t say that it works with 100% certainty, but as of now I’d say it’s safe to close this.

[houska]

Glad to hear that. Closing this issue then. If you encounter it again, feel free to write another thread!