SPZ v2

[azadbal]

Hi Aras,

Just wanted to ping you regarding the fact that we've recently updated SPZ v2 to include a major improvement to maximize the accuracy of the quantization of Gaussian rotations (you can follow the PR here).

We recommend updating your SPZ library to the latest version so that any SPZ file written with v2 can be properly read.

Thank you!

[aras-p]

@azadbal Thanks for the heads up! Do you have some SPZ v3 files that I could test an implementation on?

And yeah I was surprised that SPZ did not use the "smallest three" quaternions from the get-go; seems to be such an obvious choice. Just like I am still surprised that alpha is encoded just in 8 bits without any transformation; precision of it could be improved quite a lot by applying some curve :)

[azadbal]

Let me quote @gotoeasy's comment on another SPZ v2 thread.

https://github.com/gotoeasy/gsbox
# Convert the ply to spz version 3.
gsbox p2z -i /path/to/input.ply -o /path/to/output.spz -ov 3