PORTAL MATCHMOVE & REFLECTIONS
First challenge in this shot was to achieve a cleanplate of the floor that would allow to reconstruct realistic reflections that respect the water puddles, and reflect and distort according to the original footage.
Note: for this project, I did motion tracking, prep work, and compositing. 3D model isn’t mine.
Movement for this shot is a simple dolly out. I started off by 3D tracking the scene and match-moving the elements in it, before working on the floor cleanplate.
This cleanplate was projected on a plane at ground level from which I obtained an alpha channel from this cleanplate that would mask the reflections and distort them.
I asked the 3D artist to send me a Z-flipped render of the 3D model, so I would have an inverted version of the portal to use on the floor reflections. In this image, the alpha channel above is masking the inverted portals and applying it distortion and blur effects, to imitate the rough reflections in the original footage.
Even though this project is unfinished and the 3D is not definitive, this video below shows the reflections effect pretty well.