Question about train my own photo set

[Sunineu]

It's a great work!
When I train my own photo set with llff's params, the code will report two errors："assert len(xyzs) >= visible_points_count" in nerf_dataset.py or "Matrix inverse contains nan!" in utils.py.Some data can be successfully trained, some data will report the first error, and some data will report the second error.
I would like to know if there are issues with the training data captured or if improvements can be made from the code? If there is a problem with the captured dataset, how should the correct image be captured?