Calibration
Always Moving: 6D Poses for a Wearable Fisheye Rig
In the last post I calibrated eight ZED cameras bolted to a room’s walls so OptiTrack’s 3D positions could be projected onto each image. Those cameras never moved: one 6-DOF pose per camera is the whole answer. This post is the opposite case: a rig worn on a person, moving every frame. The goal is the same, but “the pose” is now a trajectory recovered at 20 Hz for the entire take, which changes which tools work. The rig is Homie, Ropedia’s four-camera egocentric setup for recording manipulation data: a person wears it, does a task with their hands, and we want every tracked object and finger marker to land on the right pixel.
The Missing Link: Calibrating a Sparse RGB Rig with OptiTrack
It has been a long time since I last wrote a blog post. Honestly, I almost stopped. In the age of LLMs, writing about technical topics feels pointless. Whatever you want to know, an AI will explain it more clearly and faster than any blog. So why bother? What changed my mind was running into a problem where AI could tell me the theory perfectly well but couldn’t tell me what actually went wrong when I tried it. That gap only gets filled by doing it: wiring two physical sensor systems together, watching them disagree, and working out why. That kind of experience doesn’t live in training data yet. Physical AI is full of it.