I’ve been talking with Ivan the DP about making Electric Town in 4k. Since we’ll be shooting the movie on a Red Epic (which shoots up to 5k, with planned upgrades for 6k by the end of the year) we can easily do it for the live-action, but I’ve been a little unsure about the CG side of things at that resolution. I’ve been trying to test how fast I can render that size with the resources I have, and also how the textures/models/etc actually look when rendered at that size.
So far, the results have been pretty promising. The best news is that Renderfarm.fi now handles Cycles and can break up tasks according to samples, as well, which is a great feature. So I threw 150 4k (4096×2304) frames rendered in Cycles at 2000 samples on the renderfarm to see how it would go. Each of these frames renders in about an hour on my dual quad core 2008 Mac Pro.
The results are here. As you can see, the whole sequence took about a week to render, which I think is about the same as it would have taken on my Mac Pro, and about 13 times faster than it would have taken on the theoretical single generic processor that Renderfarm.fi uses as a comparison point. Not bad!
This robot dog is really the most resource intensive CG prop to render, so if I can render this in a reasonable time, I’m not too worried about any other render bottlenecks. The Blender Sequence Editor also handled the 4k frames with no problem (although I am having trouble outputting a 4k movie file that I can read easily in VLC). Ivan’s done a fair amount of work compositing and editing 4k video though, so once we’ve got the CG frames, I think any other technical issues should be resolvable.
As for the way it looks, honestly, it’s not too bad. Fortunately, the textures I used were mostly all about 4,000 pixels wide anyway, and I don’t see any texture pixelation rendering them big. The model’s geometry looks a little too clean, and the high resolution doesn’t do any favors for bump maps. I’m going to do a bit more work on the model and textures, but in any case I think some motion blur and other post effects will go a long way towards covering those flaws up.