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RPR 1.7.239 macOS Blender 2.79b Frame 124 Animation Bug

Question asked by gelert on Nov 12, 2018
Latest reply on Nov 13, 2018 by gelert

I have recently rendered four animation sequences that were all about 240 frames in length (10 seconds) at 720P resolution with 500 samples per frame and always rendered on two eGPUs running together at 100% utilization. My scenes have been reliable during the animation creation process and test rendering phase. No shader errors. Every frame will render just fine individually. There is no reason for it to stop at multiples of 124 ish frames.


I ran three of the animations via the macOS command line. blender -b path/to/file.blend -a having already saved the Blender file with the right output directory, overwrite setting and eGPU.


The fourth animation I rendered via the User Interface Animate button and watched the render on screen.


In all instances the render output gets corrupted at Frame 124 (or thereabouts within one or two frames). One of the animations was 290 Frames and so it corrupted at F124 and then again at F250 once it was restarted.


The corruption appears as a multi coloured image or as a totally transparent PNG output file. The render continues to it's conclusion with much longer time between each frame at the initilization stage but no further frames are rendered correctly. There is no error given.


The command line as it went wrong. Notice the gap in the GPU history. The tone of the eGPU changes too when frame 124/125 happens.

Screenshot 2018-11-09 at 14.43.15.png

It is simple to kill the command line version of Blender but the UI version of Blender becomes extremely difficult to Force Quit at frame 124.


There doesn't seem to be any reason why this should happen but it happens on every animation that is longer than 124 frames!!


Hope the screenshots help.


I didn't want to test a "weedy" test project. But my little animations are not really very complex. They all have DOF and standard lighting and as I said do not crash Blender when rendering any single frame from the entire animation. Until you want to batch render the entire animation.



The resulting frame.

Screenshot 2018-11-09 at 14.44.13.png


Then again at F250 it happens again.


Screenshot 2018-11-09 at 15.23.55.png


A different scene. Rendered via Blender UI, not command line: F123


Screenshot 2018-11-11 at 11.29.03.png

Blender is unresponsive and it is difficult to force quit.

Screenshot 2018-11-11 at 11.29.12.png


Some sample "corrupted" frames.




 corrupt 0251.png corrupt 0252.png Weird-Activity-at-Frame-0126.png