Question about formula (3) derivation

[wawcac]

Thanks for your codes released. I have some questions about one of the formula derivations in your paper, and I hope you can answer it.

Specifically, I don’t quite understand how you got the formula (3) on page 4 from the formula (2). I wonder what is the idea behind this step or how to implement it. Could you please give me some hints or references to help me understand the process and principle of this step?

Thank you very much for your time and help. I look forward to your reply.

[jby1993]

This formula is derived based on the implicit integration formula. Lemma1 of this paper has a detailed derivation of a similar formula for a static scene, which you can refer to for better understanding.

[wawcac]

Thank you very much for your reply and explanation. I really appreciate your help and patience. Your answer has cleared up my confusion and helped me understand the derivation better. I admire your work and hope to learn more from you in the future. Thank you again for your time and kindness.