Fig. 4: Visualization of the 2D slice of the signed distance field (SDF) learned by CartiSurface.

The color map represents the predicted signed distance, where negative values (blue) are inside the object and positive values (red) are outside. The solid white line indicates the ground-truth cartilage boundary, which aligns closely with the zero-level set (the transition from blue to yellow/red) of the predicted SDF. The smooth and continuous iso-contours demonstrate the high-quality geometric field learned by our model.