A little Python project

I don’t program enough. Simple python programming opens up so many opportunities for pipeline tools and extending graphics applications like Blender, Maya, Cinema4D (latest versions), Lightwave (latest versions), Nuke, Hiero, and several asset and job management systems. Python is also being pushed as the main programming language on the Raspberry Pi, which is sitting next to me wanting some attention…

After Europa wrapped I started a programming to-do list that included a tool that checks for missing or bad rendered frames. I was rendering on a lot of different machines for that project and had thousands of frames to manage. I wasn’t using any render management system so there was nothing checking to make sure a frame got rendered properly except me scanning lists of files. The software that runs the cluster at school has no ability to make sure a frame got rendered properly and at home I use Blender’s simplistic network rendering ability of creating an empty frame (to show that the file exists and a free computer can work on the next frame) and then replacing the empty file when the rendered file is finished (BTW, there is a network rendering manager in Blender, but I don’t use it – yet). If a computer fails to complete a rendering there will be a blank frame left behind. A blank file will be left over if a computer fails on the school’s cluster (Callisto) too because I usually setup the files at home (turn on the “placeholder” and no “overwrite” options). While I didn’t have a lot of problems with broken files and unfinished sequences, I felt like I was vulnerable to issues that would be difficult to fix at the last minute – some frames took about 40 minutes to complete on an 8-core/16GB RAM computer.

Over the last couple of days I carved out some time and wrote a python script that looks for both missing files in a sequence and files with zero (0) bytes and then it writes out a report to tell you what’s missing or has zero bytes. It works by typing something like this in the command line:

python badFrames.py /path/to/rendered/frames 4 0 240 /path/to/logs

  • /path/to/rendered/frames = unix-style path to the directory that has the frames. In OSX, /Volumes/Media/Europa/06 (or something like that)
  • 4 = frame padding. The number 4 shows that a frame name will end with 0000, 0001, 0002, etc. This assumes number + extension, such as file0001.exr. The filename can be anything as long as the last 4 (or whatever) characters are numbers.
  • 0 = start frame
  • 240 = end frame (correct/expected end frame, not what’s actually in the directory)
  • /path/to/logs = (optional) the script creates a text file that is saved in this path. If a path is not here then it will save the log file in the same directory as the frames

There is only a little error checking going on so it could break if there are extra files in the directory, such as text files that are listed before the frames (sub-directories/folders are fine though), or you give it a path that does not exist. If people ask, I will add more error checking so it gives actual error messages. Right now it will give you a help message if something obvious is wrong. I might make a GUI for it too – more on that later.

BTW, this will not work on Windows without a few tweaks, but will run on OSX and Linux fine. I am hard coding some slashes in paths that work on unix-based systems only. It does require Python 2.7x or 3.x due to my print statements. I can change them so it works with 2.6 or earlier if you want.

Grab it here (temporary link)


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