help me refine the following paragraph "t turns out that  this additonal supervision from segmentation is actually vital for reconstruting non-rigid objects from casually captuered videos because it provides direct knowlege of how the static background and the nont-rigid foreground object shall be separated, so that different regularization can be more effectively applied to different regions of the scene. In contrast, it is actually ambiguous to perform foreground-backgraound separation purely based on motion parallax, simply due to the fact that epipolar constraints (relied on many motion segmentation methods) are not a sufficient condition to determine whether the motion corresponds to different pixels are from the same rigid motion. " Give two different versions of responses. Please separate the responses with 6 asterisk symbols: ******.
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