This was my techniques project at university. The brief was to create a one-shot impressive effect, that's it. I chose an ice spreading effect, perhaps because (as I started to find) at that time no-one had done it well before (seriously, check out all the old ice spreading effects that you think you know - they're probably just a blue-ish wipe, with maybe some noise, and perhaps some practical dry ice. Now there's loads that have been done really well, such as this from Glassworks), perhaps because I thought it could have been quite an evocative effect, especially if I made it Jack Frosty-spikey, and sort of sparkly and tingly. 

 

I thought it would be a good idea to film the backplate using a handheld camera, using a selection of everyday simple objects lined up against the wall outside my flat. I liked the idea of the effect spreading from one object to the next, affecting each in a different way due to position or shape. Unfortunately, the handheld approach and a bit of a cockup during filming meant it was really difficult to track (well, Uni's about learning, right?). The end result is the best of a few attempts, but it still slips here and there. 

 

The effect itself went through many stages of look dev, but I quickly realised that one shader or effect wouldn't do all the things I wanted to, so in essence the idea was to have 4 or 5 layers of effects all driven by a developing mask which grew over each of the (UV'd) shapes. 

 

The mask itself was made in Nuke, and is really just layers and layers of pine tree photos comped together, with a few ramps and rotos, and the blackpoint animated over time. Seems weird, but the idea is that with all the light wrapping and image antialiasing around the smaller branches and needles, the blackpoint grew from the core of the tree outwards to the very tips. Mess with this enough, add a few motion blurs, and you have a pretty convincing organic-looking mask, which has a nice randomness, and can recombine into itself (unlike l-systems, which I tried first). Plus, it took about a day, which, given my tracking problems, saved my bum.