Hey all!
Alex here.. As a VFX artist in films/episodic television and animation, I got to work on some truly challenging projects. I thought Id take a minute and highlight some of them via blog posts, with the idea that fellow VFX professionals, film enthusiasts, people curious about VFX and/or my own mom might enjoy reading about these challenges and solutions to them.
Well, without further ado lets talk about Shazaam: Fury Of The Gods! (Everyone usually says at this point, the Sinbad movie? -- Nah, that was Kazaaam from the 90s)
In the second Shazaam film our primary challenge was a shot involving many statues crumbling in the Parthenon museum of Athens, upon the whim of a capricious DC-universe-adapted greek godesses Hespera and Kalypso. This was done over at "Method Studios" which has since became the mighty Framestore.
Here's a blurb about the show: from Framestore via Sean Schur. Sean was the VFX supervisor on the show: https://www.framestore.com/work/shazam-fury-gods
And here's part of the shot on my demo reel:
(TBD)
The primary challenge was in orchestrating the vast amounts of dust in what we call an "art-directed" way. Luckily (or unluckily) everyone from Sean to the director David Sandberg (a guy who has serious VFX chops as we learned) were very well versed in laws of composition! The various sculptures would not only need to crumble, but also emit dust elements! For these my lead Sandro Di Segni and I came up with the affectionate term "snakies". Each statue would crumble and then the dust form the statue would have to crawl along the ground sanke-like in a very composition-y "rule of thirds" way towards the ultimate target of the shot.: Two ladies petrified into stone on top of set of steps. Ultimate aim of the dust was to completely cover the camera along with the unfortunate ladies by the end of the shot. Big challenge was orchestrating all these elements to work in concert with each other.. "That snaky is spinning the wrong way! Its covering up too much of the camera too early!".
The timing on the shot -- how fast / slow things take was super-tricky. Initially we wanted to show off the crumbling starting from smallest rocks on the outside of the big Zeus statue, then peeling away towards the inside, But the client / director did not want to "make a meal of it" but rather preferred the fast collapse with "comedic timing" and disappearing of the rocks you see in the final shot. What's fascinating about the VFX process, is that one does not at all know what's in the mind of the director, and its a sort of a puzzle to figure out. One made especially challenging by the fact that usually only the supervisor is on creative calls with director, not the artists themselves. We had no idea how dust-dominant the shot would become, and how much orchestration of the dusty snakies would have to take place!
Lets talk technology, and methods that got us there on time and on budget:
Side FX Houdini - Essential software for most VFX . It has very robust system for crumbling (RBD simulation) getting more robust every year. (Now with Machine Learning!) For example guiding each snaky forward as well as giving it a 'vortexy-spinny' feel can relatively easily be achieved wtih one of my favorte tools: GasCurveForceDOP.
Divide and-conquer approach: Did we try to a) Emit the dust from each crumbling statue b) guide that dust all the way to the two ladies in one simulation? No we did not try that.
Rather we came up with a way to controllably add dust once rocks hit the ground and guide that dust towards its goal. That way, if director wants to have a particular "dust snaky" be less or more present we can easily adjust that without having to redo the whole crumble simulation. Divide and conquer approach, modularizing a problem works in any kind of industry, especially the smoke-and-mirrors world of VFX.. I even did a SIGGRAPH talk about it back in the day:
Organization/ Presentation: With so many various crumbling simulations to present, it was important to keep things organized. Sandro came up with a houdini way to a) label every statue and b) create quick flipbooks (previews) of every statue collapse along with the assigned label. This allowed for quick reviews and we knew exactly which statue simulation was being addressed/discussed in rounds/dailies.
Simplification: As artists we want to do complex things! Layers and layers of fine peeling/shattering looks great on a reel. However once we realized that the brief asks for a quick comedic collapse we came up with simpler "constraints" systems (these stick rocks to each other) + controlled activation of crumbling transition.. Rather than break constraints with simulated "forces" we animated the breaking of constraints based on an art-directed and quick wipe progression. The only problem with this approach was that the as constraints on the bottom were broken we would have floating "islands" rocks disconnected, hanging in mid air Avatar/Pandora-style. This was easy-enough to solve procedurally though, as we could detect when an island is disconnected from the ground and activate it at that point. Another simplification (that was part of the client brief as well) -- the rocks dont stick around too long on the ground. They turn to dust very quickly..-- so we created a setup that would essentially shrink the rocks while emitting dust giving the feeling of the final effect!
All in all this was a challenging shot that lasts for 21 seconds (a really really really long time in VFX world).. The main challenges such as directing the dust, and timing were artistic rather than technical.. All that is fine by me! Great job by all artists at Framestore/Method.. (I mentioned our awesome Lead Sandro, but on this particular shot wanted to also shout-out Igor Lementy who came in at 11th hour to help out on a particularly gnalry snaky--the one that comes out of Zeuss, nice one Igor!!)