
Post-production on Your Face is a Saxophone is going quite well. I was terrified that the whole thing would still be rendering by the first week of February, but it turns out that I’ll probably finish right on time.
I did a few things to speed the process along:
- I lowered the amount of motion blur samples from 8 (the default) to 3. This means Motion will only use 3 different variations of each frame to create the blur effect, which is A) faster and B) actually looks better for my art style. There are some shots (notably the entire opening scene) which still have 8-sample blurring, which I decided not to re-render because it would waste too much time.
- I set the render quality to “Normal” instead of “Best” for certain shots with many objects. This was a painful decision, as “Normal” quality creates some very noticeable jaggy lines, but I can’t afford to wait 5 hours for 2 seconds of footage right now.
- I optimized a chair model which had apparently been causing a major performance hit this entire time. Because Motion can’t use actual 3D models, I decided to give the chair an illusion of depth by duplicating the graphics for the seat and the back about 328523857 times. This looked decent, but was apparently an enormous resource hog. I discovered that I could live without the depth effect, so I did.
Additionally, I noticed yet another piece of evidence that Apple Motion was programmed by monkeys — not even trained monkeys, just garden-variety, crap-throwing capuchins:
Another one of my time-saving techniques is to render the background separately from the characters, and composite them in Final Cut. This requires the characters to be rendered with an alpha channel, which is data telling Final Cut which parts of the image are supposed to be transparent (i.e. everything but the characters). Motion has the capability to output the alpha channel by selecting the “Color+Alpha” option when you render. This works perfectly, except for when it randomly decides not to.
This wouldn’t be a huge issue if I could tell whether Motion was forgetting the alpha channel while it rendered, in which case I could stop the process after one failed frame and start over. Unfortunately, the only video-playing piece of Apple software that seems to have any idea what an alpha channel is is Final Cut — everything else (i.e. the Preview window while Motion is rendering something — see picture above) displays transparent portions as pure black. Thus, the only way to know if there’s a problem is to load the video in Final Cut, after spending between 10 minutes and 7000 hours waiting for it, and see if the black parts go away. If they don’t, then I just wasted 10-420,000 perfectly good minutes of my life, and have to do it all over again.