New RL paper: C-Slerp learns 5-cube stacking from scratch with no rewards or pretraining

ben_eysenbach · x · 2026-10-20

Ben Eysenbach shares a goal-conditioned RL paper (9 months in the making): C-Slerp solves extremely long-horizon tasks like 5-cube stacking from scratch—no prior data, no rewards, no pretrained models. It learns hyperspherical contrastive representations and infers waypoints in closed form. He frames it three ways: hierarchical RL with a closed-form high-level policy; a planning algorithm mapping nonlinear dynamics to a latent space where planning becomes a Brownian Bridge; and representations enabling horizon generalization. He also reframes exploration: representations encode environment structure, unseen goals get mapped into them, and representations update when the goal isn't reachable—explaining how agents reach goals random exploration would never stumble upon.

Original post →

More from Embodied

Embodied channel →