Rethinking 3D Robotic Perception: Elastic Voxel Representation with Splatting Distillation

Language-guided robotic manipulation is advancing rapidly with Vision-Language-Action (VLA) models, yet faces fundamental challenges in 3D perception. This paper addresses two critical challenges: the scale elasticity requirement for simultaneously processing coarse environmental context and fine manipulation details, and the scarcity of action-annotated training data. We present Splat-Actor, a novel robotic manipulation framework that introduces two key innovations. First, we develop an elastic voxel encoder that combines multi-scale processing with selective tokenization, enabling efficient 3D spatial reasoning while adaptively focusing on informative regions. Second, we propose a depth-constrained feature distillation framework that leverages Gaussian Splatting to bridge 2D and 3D representations, transferring rich semantic features from pre-trained vision models to enhance 3D understanding. Extensive experiments across 10 manipulation tasks with 166 variations demonstrate that Splat-Actor achieves a 6.8% improvement over state-of-the-art methods while maintaining the computational efficiency.