Version: (using KDE 4.3.1) Installed from: SuSE RPMs In Marble, there is the ability to shade the areas of the globe that are in night to make them appear to be in shadow. However, the terminator, the border between the day area and night area, is inconsistent. In the Earth maps that support it, as well as Venus, the border is a smooth gradient from light to dark. However, in the Mars map and all of the moon maps, the border is abrupt, with on point being totally in day and the other being totally in night. I personally prefer the smooth gradient, it is much more realistic, but I think it would be better to pick one or the other and use it for all maps.
Confirmed in KDE SC 4.3.90.
This is not a bug but a feature: Earth and Venus have a thick atmosphere. Hence the twilight zone covers several dozen kilometers for both. Mars has got a thin atmosphere and the moon has got none. Therefore there is no significant twilight zone.
(In reply to comment #2) > This is not a bug but a feature: Earth and Venus have a thick atmosphere. Hence > the twilight zone covers several dozen kilometers for both. > > Mars has got a thin atmosphere and the moon has got none. Therefore there is no > significant twilight zone. Oh wow, thats good to know, I change the status.
Created attachment 40750 [details] Moon terminator comparison A comparison between a photograph of the moon's terminator (left) and Marble's representation of the terminator (right).
Created attachment 40751 [details] Mars terminator comparison A comparison between a photograph of Mars' terminator (left) and Marble's representation of the terminator (right).
I looked at some photographs of the moon and mars, and those pictures seem to show a gradient from dark to light. It may not be as much as it is on Earth or Venus, and I am not sure why it is there at all, but it does not look like the solid line marble shows. I have attached some comparisons between the photographs and marble's representation, with the photograph on the left and marble on the right. Of course in the photographs dark is much darker than it is in marble, but it also does show a little gradient.
Hi, Yes, there are multiple things that contribute to the shading. In addition to the effects of the atmosphere there is the pure surface shading and the highlightning/reflection. I haven't really looked into the latter. Also for the moon there are the craters which drop shadows (which is something we can't easily add for Marble with the current approach).
Yes, I figured that doing the crater shadowing was infeasible. But the crater shadowing only appears to account for part of the gradient (at least for crater large enough to be seen in Marble, smaller craters probably average out), it looks like something else is causing the rest. As for the mechanism, I don't mean to sound trite but is the mechanism even that relevant? At least to me what is important is making it look as accurate as possible given the software's limitations. The current representation does not seem accurate to me, at the very least it does not match pictures of the bodies in question. This would lead me to conclude that this is a bug, given that photographs of the moon and mars show a gradient, marble is capable of showing gradients, but the moon and Mars maps in Marble do not show a gradient. So my opinion, at least, is that this bug is valid and should be reopened.
Thank you for the bug report. As this report hasn't seen any changes in 5 years or more, we ask if you can please confirm that the issue still persists. If this bug is no longer persisting or relevant please change the status to resolved.