Pacing and Rendering

Being in this for over ten years now, I see a lot of questions pop up regarding errors during renders of animations that are well over ten seconds which are set for at least 30 frames per second (fps).

In almost All cases, we don't need or even want to render that many frames of a single sequence. Animate, maybe. But then render the sequence in several sections if it has to be that long. There are many reasons for this but I think the biggest two are these:

  • Audience - Most audience participants don't even realize that any single sequence is usually shot (in film) over many camera angles. Or that, this is the reason for their boredom, when this is not the case.
  • Efficiency - rendering more than a few seconds of animated sequence is often being wasteful of your time and resources - and can even overheat/harm your computer.

As an example, the next time you watch a movie or TV show (aside from news or documentaries) pay close attention to how many times and how often the view switches to a different camera angle. You'll see that we don't often see more than 2 or 3 seconds from any one angle. We will see longer ones, even longer than 6 seconds, but those are more rare.

This is not Always the case but instead of trying to find flicks that have long sequences just to prove this rule incorrect, try instead to heed what's happening with the pace of it all. We see a face, and then his eyes slowly turn to his left (2 seconds total - even though it actually feels longer due to drama) next we see what he's looking at through his eyes - with a slight, spooky Dutch Angle (3 seconds or even much less) and then we see his face again for a single second and then we see him from the angle to which he's looking, as if what he was looking at has eyes, and we're looking through those eyes (1 or 2 seconds).

Don't think of it as cheating or that shorter numbers of frames is less impressive to the CG artists out there. Think of it as dramatic pacing or action sequencing. Think of it as a tried and proven method of keeping your audience glued to the screen to see what happens next!

Render Output Format

Do we render straight to AVI or MOV, or do we render to Image Sequences?

I've rendered straight to AVI for years. I was fine with that. But I was also just learning my way, mostly doing test renders of animation timing, lighting, textures, effects, etc., - seeing how it all looked in motion, but only to see it, then delete it.

Now that I'm actually working toward bringing this into my VFX software and then into the Editor, I've learned to completely switch to Image Sequences in a lossless file type. I use PNG, but there are many to chose from, like TIFF, BMP, etc., Just be sure to pick one that your editor software can accept.

One of the big advantages to this is the inevitable error during an animated render. Rendering software is doing an unbelievable amount of work just for each single frame. If something goes wrong during an AVI, the file either closes where it is and is still viewable, but missing the rest of the unrendered frames or it fails completely and we get a file that cannot open.

With Image Sequence rendering, we can restart the render at the first lost frame and continue on. We end up with the entire sequence in one place, but it's a whole pile of images.

My biggest complaints was that I wanted to actually 'see' the animation after it renders. I could double-click my AVI and they'd launch in my Media Player Classic.

3d Rendero, from Carrara Cafe turned my on to an Open Source software called DJV, which plays our Image Sequences at whatever fps speed we want, and loops so we can really study the sequence we've rendered.

Using dynamic hair, rendering to Image Sequence has been a real boon to my work. When I made the "Introducing Rosie 5" video, I didn't go back and fix things that I could have. It was more of a demo than a finished work. We see her hair flicker in places. If we slow the video down we'll see that the flicker comes from the hair not rendering properly. Don't get mad at Carrara for this - it's quite magical that it does what it does so well! Instead, go to the bad hair frame and render it again, replacing the file with the faulty render. This second time rendered has never failed me yet. If it does I'd just render it again until it's fixed. Simple!

Hair isn't the only thing that can go wrong during an animated render sequence. Volumetric effects might have an issue for a single frame, an animated tree might have this... the point is that, by rendering to Image Sequences we can fix it!

I hope I've given you some help in working out the pacing and rendering of your vision. I'll be adding to this in time, but these thoughts should launch you toward the right direction.

Remember to pay attention to camera switches during your favorite shows. Watch the 'over-the-shoulder' shots as people converse. Observe how quickly the screen switches cameras during an action sequence. If it helps, turn the sound off completely and only pay attention to what's visually in front of you. This can help you focus on the screen instead of getting wrapped up in the story.

Good luck and Have Fun!!!