what are possible application and use of rendered_depth & rendered_alpha?

[pknmax]

1. does this make trained scene representation/rendering better than original 3DGS rasterizer?
2. is there a way to use this to make loss term used in 3DGS more efficient and better?

[ansj11]

it is useful to use rendered_alpha to calculate mask loss in some object reconstruction cases. rendered_depth can also provide some guidance e.g. depth loss between rendered_depth and monocular depth.