Sinners was shot on IMAX 65mm film — and needed Michael B. Jordan to play twins, Smoke and Stack, in the same frame. A traditional face swap couldn't survive that resolution, so Rising Sun Pictures (RSP) built a new approach: the "Halo rig," a shoulder-worn array of ~12 cameras around Jordan's head, feeding a GaussianAvatar pipeline that used radiance fields (Gaussian splatting and NeRFs) to generate the synthetic training data their face-replacement models needed. I sat down with RSP's Oscar-nominated VFX Supervisor Guido Wolter and Machine Learning Lead Dr. John Bastian to go deep on how it actually worked — from wrangling 52 TB and 125,000 faces, to editing expressions with FLAME parameters, to why they never put a splat directly on the final plate. We also get into where Gaussian splatting is heading in VFX: environments, relighting, crowds, set survey, VR, and native support landing in Nuke and Houdini. RSP contributed roughly 100 of the film's most technically difficult shots. ...