This is one of those jobs that pushes our technical tricks to the limit, from the shoot itself that required lots of time and effort to the actual paper carving and of course, paper landing in a natural way but directable and for this we used every single tool under the sky, from XSI to Maya to Houdini, from Zbrush to… anyway… almost all of them.
And on the journey I had the luck to work again with extremely talented people that managed their chunk in a such a brilliant way the whole project was a breeze.
Approach
Starting with a studio shoot we planned to build a rig for the camera and also a air sucking device so we could get in camera as much as possible and instead of doing a fully CG job just substitute the backgrounds with live action from a location shot… the result as spectacular when working at high speeds and highly poetic imagery although every time we needed to lift a lot of paper the air sucking device was limiting us a lot.
In that sense my estimations of paper weight and air flow proved right, the machine was not powerful enough to lift the paper but it was mid air it managed well.
Therefore we build a real life 1⁄3 scale of the whole thing with real paper that was gorgeous to photograph but we could not make the paper land where we wanted nor we could lift the paper naturally so we had to take over some of the work that was intended to be done in camera and extend the effect.
In this case some of the close ups were also done fully in CG due to the highly choreographed requests from the director and agency so extensions and even full substitution like this case was the norm on some sections.
The carving process of the car proved a nightmare due to the size of the mesh to cut, for this the process I devised was to use 3DCoat to generate a voxel volume that was used to generate a second mesh that was closed (the positive), with manual tweaking of wholes (like the ones on the wheel archs) and elements that were sticking out as this was not possible to do physically.
The principle was, this should be possible to build so after the whole cleaning operation we processed a boolean operation in Houdini to generate the negative to a set of rough boxes that defined where the paper was placed.
Once the boolean was done for each frame, and this took around 6 hours to the resolution we were working we would go back to the positive to iron out the kinks and strange effects.
Then we created a shader in Houdini to generate the paper taking in consideration paper tones, rotation, bendiness, offset of paper as we observed from the shoot real life elements. This took a lot of time but was critical of course.
To make the paper land we exported the top of the boxes to Maya where were we simulated the paper in reverse and after approval take them back to Houdini to assemble the scene and we created a very complex function to identify the paper that was about to land and we deleted it because we realised this was not a beautiful element, the director and us really wanted a constant flow rather than a real event of landing.
The render times were not bad at all but processing the files to be sent to the farm was very slow process due to the scale… at the end we were so happy with the results that managed to celebrate on the pub like there was no end.
Credits
Director: Nicolai Fuglsig Agency: MJZ Production: BBH Task: VFX Supervisor / Lead Artist
