The VFX of Take Off Your Clothes
Take Off Your Clothes is a horror short film about the horrible conditions modern slaves have to endure so we can have cheap clothes. It’s the follow up of our non-commercial socio-critical short film project Immaterial and it was written and directed by my friend Felix Charin, who also wrote for How to Sell Drugs Online (Fast) for Netflix and 4 Blocks. Both TOYC and its predecessor, the yet publicly unreleased Melania, were presented at short film festivals, for example in the Chinese Theatre for HollyShorts.
My role in the production was everything VFX, using Maxon Cinema 4D with Redshift, the Foundry Nuke for compositing and SideFX Houdini for simulations. All in all, about twenty shots were edited by me in about two months in my spare time.
To start it off, we wanted to have a thematically fitting title sequence, so we chose to show it as an embroidery while reminding of flowing blood with a touch of the Westworld opening titles.
I mostly created it in Cinema 4D with its Motion Graphics tools. The threads are made of individual fibres and I used Houdini to create the embroidery splines from the title’s letters.
The biggest effect sequence was the burning pile of clothes in the finale. I used this as an opportunity to learn Pyro FX in Houdini. As usual for simulations, it took a while to get the right feel, but in the end it turned out quite believable.
There are surprisingly few tutorials for Pyro FX that go beyond just setting up a simple scene, so I had to experiment quite a lot to get everything to look better than (or at least comparable to) using elements from ActionVFX, for example.
After simulating in Houdini, I imported the resulting vdb sequence in Cinema 4D and rendered it with Redshift.
For realistic looking fire, it’s best to render it to linear exr files with a nice artist driven volume gradient in emission (I never got a realistic look with those default black body gradients) to get those high brightness values over 1, then putting it through an approximation of how real cameras react to bright flames at the exposure it’s set to and tonemapping it in the end, before compositing it over the plate.
First I converted the original plate from log to linear, degrained and tracked it.
Then I rendered the lighting effects of the flames on the proxy geometry of the pile of clothes as an AOV and used it to get an approximation of how the flames would light the scene.
On top of that I composited in the smoke with some grading.
After doing some basic color grading I used my favorite glow K_NaturalGlow, which gives the whole image a nice tint, and of course I also put on some chromatic aberration I matched to the plate.
Cameras react to bright lights in a specific way, so I used LensKernelFFT to get those artefacts. The result is tonemapped with filmic tonemapping with desaturated highlights. I used shot on black elements of real fire as a reference to get appropriate values for my CG flames.
Once everything was merged, I regrained the resulting Footage with the amazing DasGrain gizmo, which I used to regrain on every shot I touched. Because we filmed with very little light the footage is quite noisy and elements added without matching that would look out of place. This is the final sequence:
Together with my colleague and fellow nuke artist Konrad Hofsäß we created a Nuke script for the door viewer. We set it up in a way that the bright reflective bokehs react to the scene behind it, so it’s believable and not just a static overlay.
In addition there were a lot of little shots that needed fixes or changes. In a few shots crew was visible in reflections or at the edge of shots which I removed by tracking on over painted parts.
In one scene the witch stood next to our main character, where she should have been alone, so I used the concealed parts from a different shot (where the light was on), matched the colors and perspectives in photoshop and merged it in Nuke. In the end, it turned out really well.
Of course, some wire removal was also necessary. At first I tried using the F_WireRemoval from Furnace that was integrated in Nuke, which didn't work out for most shots. Often it was just easier to track the shots and use the rotopaint tools. I would still like to find a more efficient workflow though, as it was a lot of manual work.
This was an amazing project where I learned a lot. Especially when watching Melania, which I comped in After Effects, and Take off your Clothes side by side, I think I improved a lot.
It’s always a good idea to challenge yourself for personal projects, even if there would be easier ways to get there. I learned a lot about Houdini and Nuke and I have many ideas of what I want to learn and improve in the next short movie.
Thanks for reading, don’t hesitate to contact me if you have any questions or comments!
