The scaling for gaussians

[Xin-97]

Hi authors, thanks for your great work. I want to ask why scaling is set around -5. Why is it a negative number? Thanks!

[zjwfufu]

The scaling is also activated by a exponential function as in the original 3DGS. exp(-5) corresponds to about 0.006. This activation is to map the scaling which has small order-of-magnitude into logarithmic coordinates, thus facilitating optimization.

[Xin-97]

Hi @zjwfufu, thanks for your reply. I notice that in the paper, they calculate S_ref in Eq. 8, do you know how to do the calculation to get S_ref=-5.0? Thanks.