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Slow-motion video reference

Add Comment! By David Rosen on July 13th, 2009

Whenever I am animating a movement or coding a new special effect, I like to find out as much as possible about what is actually going on. It is easy to capture the basic essence of any effect: lightning makes a forking flash in the sky, big water splashes are white and foamy, a gymnast rotates 360 degrees when she flips. However, all of these effects are so engaging to watch largely because they are so complicated and unpredictable -- there is more detail going on than we can possibly grasp in real-time. If we just mimic the basic idea and leave out the details, the effect becomes generic and boring.

So how do we capture these details, if they are too subtle to understand in real-time? We use slow motion video! Once you can simulate an effect well enough that it looks good in slow motion, it will look perfect at normal speed! High-speed cameras are becoming more and more common and affordable, which makes it easy for us to find slow-motion footage of almost anything online. Here are some slow motion videos that I found interesting:

Freerunning

Ever since Prince of Persia: Sands of Time, parkour (and its flashier cousin, freerunning) have been steadily increasing their presence in games. There are even several games that are entirely focused on parkour, such as Mirror's Edge and Assassin's Creed. In the world of Overgrowth, the rabbit's primary advantage is his speed and acrobatic ability, so we will be expanding on the acrobatic moves that were available in Lugaru. We're not using motion capture, so to make these movements look good, we have to understand parkour movements in detail with an animator's eye. The secret to animating parkour movements (and performing them) is to have very smooth transitions -- sudden changes in velocity break bones and tear ligaments, but smooth ones are safer and more comfortable. If you want, try watching the video again, and pay attention to how the freerunners' bodies squash and stretch to cushion landings and spread out impacts.

Lightning

This slow motion video shows how fork lightning works, from a visual standpoint. The cloud sends several bright 'feelers' down to find the path of least resistance. Once the first one 'finds' the ground, there is a very bright flash along that path, greatly illuminating the cloud. Of course, at normal speed, this all looks like it is happening at the same time. However, seeing it broken down like this gives us insight into how we can generate the lightning in the first place, and how we can determine where it should strike.

Splashes

I watched the entire Planet Earth series for reference for locations in Overgrowth, but found that its slow motion footage was helpful as well. It showed many splashes in slow motion, which provided a lot of time to contemplate what the water was doing, and how we could simulate it. It seems to me that when a large amount of water is thrown into air, it starts out as one amorphous mass, which then separates into a number of different membranes, which then collapse into ropy, linear connections, which eventually split into individual droplets. What initially seems chaotic and hard to simulate becomes a fairly simple progression of 3D volume to 2D membrane to 1D string to 0D droplet. I haven't started working on this yet, because it is not really relevant to Overgrowth, but I feel confident that the next time we need a big splash, I'll know where to start!

And everything else!

There are countless other effects that are difficult to understand without seeing them in slow motion, including muzzle flashes, bird wing movement, explosions, impacts, fire, and so on. I usually find high-speed footage by accident, or by searching on youtube. Do you know of any other good sources of high-speed footage, or have any links to interesting high-speed videos?