Robot-frame future-delta training for viewpoint-robust VLAs
VLA teams pooling demonstrations across camera setups need policies that predict physical consequences without relearning camera-to-robot transforms. WALA gained 21 points on RoboCasa by supervising semantic and geometric future deltas; robot-centric pointmaps improved π₀.₅ by 7.6 points and widened their advantage at unseen camera placements. Together, these results suggest expressing future geometry in the robot frame before latent-action training.
Add a decoder that predicts future robot-centric pointmaps or their deltas, centered on the current end effector. Keep WALA’s semantic target, and train the action head against the same coordinate system. This directly couples predicted scene evolution to executable motion.
Run a low-data test with fixed-camera training and unseen-camera evaluation. Compare depth-delta, camera-frame pointmap-delta, and robot-frame pointmap-delta targets. Use a pilot decision threshold: stop if the robot-frame target improves unseen-camera success by under 5 percentage points or lowers fixed-camera success by more than 3 points.