Hi - I'm pretty much a noobie at celestia and I'm putting together some scripts for presentations. I downloaded and installed the Mars surface maps level 0-4 by John Vliet over at the Motherlode. After a bit of wrangling, I finally have the high res selected (using the <shift><r> keystrokes). Well, kind of.
One major problem seems to be that the lat/lon is off. That is hovering over Mons Olympus and shifting to med res and the volcano is no longer directly below but well off to the side. Is there some sort of alignment necessary?
The second is that how do I know or force the use of the various levels of the High Res? Does Celestia change resolutions automatically? Is so what triggers the shift? As I get closer to the surface I see no noticeable change in resolution, or is it just too subtle to see going from level 0 to level 4?
Thanks in advance!
High reolution selection
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Re: High reolution selection
John will have to comment on his map.
Celestia v1.6 has three directories which can be used to contain maps of different resolutions. You can select high, medium or low resolution in the Render menu. If no map exists in the corresponding directory, Celestia will use the next lower resolution map. It won't use a map in a higher resolution directory.
When Celestia is using a single surface map image, the on-screen resolution is generated by the graphics hardware. Surface textures in the DXT/DDS format can include maps with several different resolutions. The appropriate one is chosen by the hardware. When viewed from a great enough distance, several map image pixels are merged together to generate a single on-screen pixel. When you get "too close", the individual map pixels are smeared across several screen pixels. How this merging and smearing is accomplished is usually controlled by the antialiasing and anisotropic filter settings in the graphics driver. If they're set to "application controlled," you can set the level of antialiasing in celestia.ctl.
A map which is in Celestia's proprietary Virtual Texture format contains lots of tiles at different resolutions. The creator of the map decides which tiles exist at which resolution.
Celestia v1.6 has three directories which can be used to contain maps of different resolutions. You can select high, medium or low resolution in the Render menu. If no map exists in the corresponding directory, Celestia will use the next lower resolution map. It won't use a map in a higher resolution directory.
When Celestia is using a single surface map image, the on-screen resolution is generated by the graphics hardware. Surface textures in the DXT/DDS format can include maps with several different resolutions. The appropriate one is chosen by the hardware. When viewed from a great enough distance, several map image pixels are merged together to generate a single on-screen pixel. When you get "too close", the individual map pixels are smeared across several screen pixels. How this merging and smearing is accomplished is usually controlled by the antialiasing and anisotropic filter settings in the graphics driver. If they're set to "application controlled," you can set the level of antialiasing in celestia.ctl.
A map which is in Celestia's proprietary Virtual Texture format contains lots of tiles at different resolutions. The creator of the map decides which tiles exist at which resolution.
Selden
Re: High reolution selection
OK, so the level resolution is not controllable (per se). I can live with that. So I need to find a higher level of detail to get what I want.
Thank you!
I will await John's reply regarding the mapping positions. A little more info - Olympus Mons should be centered at 18.6N and -134W. In med res that is correct. In the high res I show it off to the west about 10 degrees. But a little disconcerting is the "foreshortening" effect I'm getting. the volcano is a "circle" but in high res I'm seeing more of an ellipsoid with the major axis North/South. If the East/West components are "squeezed" then this could account for both the ellipsoid and the incorrect longitude. Indeed I just verified - it looks like the latitude is correct, the longitude is definitely off/squeezed. Any ideas on what might cause that? Hopefully John might know?
Thank you!
I will await John's reply regarding the mapping positions. A little more info - Olympus Mons should be centered at 18.6N and -134W. In med res that is correct. In the high res I show it off to the west about 10 degrees. But a little disconcerting is the "foreshortening" effect I'm getting. the volcano is a "circle" but in high res I'm seeing more of an ellipsoid with the major axis North/South. If the East/West components are "squeezed" then this could account for both the ellipsoid and the incorrect longitude. Indeed I just verified - it looks like the latitude is correct, the longitude is definitely off/squeezed. Any ideas on what might cause that? Hopefully John might know?
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John Van Vliet
- Posts: 2948
- Joined: 28.08.2002
- With us: 22 years 5 months
Re: High reolution selection
--- edit ---
Last edited by John Van Vliet on 20.10.2013, 08:28, edited 1 time in total.
Re: High reolution selection
mmm ok, I did exactly what 1.1 said to do in that post. I will double check it in the morning and try again. Very odd, because the Rr does indeed work in 1.5.0 Celestia. Guess I will have a go at the more elaborate setup further down in the referenced post.
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John Van Vliet
- Posts: 2948
- Joined: 28.08.2002
- With us: 22 years 5 months
Re: High reolution selection
--- edit ---
Last edited by John Van Vliet on 20.10.2013, 08:26, edited 1 time in total.
Re: High reolution selection
Excellent! Thank you. It's working fine.
BTW I am using Linux - Ubuntu - and though my laptop is a 2GHZ 2GByte machine it definitely has trouble "going through" mars to get to the other side. I've speeded things up by using a shell session instead of gnome and as long as I don't go "through" mars everything works fine. Amazing detail!
Again, thank you for the walk through. I'm sure others will find it very helpful as well.
BTW I am using Linux - Ubuntu - and though my laptop is a 2GHZ 2GByte machine it definitely has trouble "going through" mars to get to the other side. I've speeded things up by using a shell session instead of gnome and as long as I don't go "through" mars everything works fine. Amazing detail!
Again, thank you for the walk through. I'm sure others will find it very helpful as well.