Specialists from the Apple Machine Learning Research division have published a paper dedicated to studying positional encoding methods in transformers that process tokens from a set of images with known capture parameters. The authors note that existing absolute or relative encoding schemes do not meet key requirements: uniqueness of patch encoding, attention invariance to SE(3) transformations with multi-scale similarity, and adaptability to scene geometry.

To address the identified problems, researchers introduced a new approach called RayRoPE (Projective Ray Positional Encoding). This mechanism is specifically designed to fill a gap in multi-view attention technologies, allowing models to more effectively account for spatial relationships between different viewpoints of the same scene.

The development aims to create a system capable of uniquely encoding image fragments and flexibly responding to changes in the geometry of the surrounding space. The proposed solution is positioned as a response to the limitations of previous methods, which failed to simultaneously ensure all necessary properties for high-quality processing of multi-view data.