Hleb Valoshka

These artifacts are caused by the fact the Celestia uses per-primitive shading instead of per-pixel one. This decision was made because per-pixel calculations will slowdown rendering and without gamma correction...

But linear->sRGB conversion makes the border between lit and unlit parts too sharp. Such image  is then converted into the 1st one in the previous comment.

it doesn't matter whether we use a simple formula or a more complicate one. And the image you posted in the very beginning of the issue looks the same.

It really looks like some textures should be treated as they are in linear space despite the presence of sRGB metadata.

 There is a progress moving stuff to fragment shaders.

it seems that wayland is working now, sop closing this

Win native UI is doomed as nobody wants to maintain it. I don't think this issue will have any care.

Not yet, but Qt is the only UI which has support.

In 1.7 we have night texture in an eclipse zone: 

Fixed in 1.6.4-2 available from https://celestiaproject.space/deb.html / https://celestiaproject.space/ubnt.html