Robots change the scenes they perceive. A hand enters the frame, objects move, and the scene at
the end differs from the start. Yet the perception models on these robots are chosen from
benchmarks of frozen scenes. This paper asks how much that mismatch matters.
We introduce RPX,
a benchmark of 100 real scenes with 70 everyday objects, recorded with robot-grade sensors
before, during, and after manipulation — ∼133K annotated frames. We
evaluate 49 pretrained models zero-shot on six tasks (65 evaluations): image depth, video depth,
multi-object tracking, relative camera pose, and two forms of visual question answering.
Two numbers summarize each model: phase robustness Φ from a repeated-measures MANOVA
and worst-phase quality 𝒥min. The results are not subtle. Every depth and
tracking model and 20 of 24 VLM evaluations change significantly across phases
(p<0.001); near-range video-depth error grows 2.0–4.4× while the robot
acts, every tracker falls to Φ = 0.21–0.55 on transitions through
Interaction, and the best in-context grounding reaches only
𝒥min = 0.23. Relative pose alone holds steady
(Φ = 0.86–0.97) — and it is the one task Interaction is not evaluated on.
Rankings also change from task to task. The model that tops a static leaderboard is not the one
that keeps working once the robot moves.
RPX
tells them apart — and, because every failure is localized to a specific phase and scene, gives
model developers the diagnostic structure to see where a model breaks, not just that it does.