t1metraveller
08-27-2008, 04:25 PM
Out of box, several factors concerning the sun and moon are not prototypical.
**The Problems
1. Sky Traversal is Opposite from Normal
If a route is in the northern hemisphere, the sun and moon traverse the sky in the north instead of the south. Routes in the southern hemisphere are okay, because the sun and moon traverse the sky in the north where they should (yes, I know this is not true in certain seasons for latitudes between the equator and 23.5 degrees).
2. Shadow Length is too Short
Sun shadows are way too long for any given time of day. Shadows at high noon are as long as they would be at 3 or 4PM. This also limits the overall lighting at the noon hour since the sun is not as high above the horizon as it should be.
3. A Minor "Nit" Problem with Sunrise/Sunset Times
The TimeOfDay file (there is only one) is set up for Spring (SEASON_SPRING), I presume as a compromise for all seasons. Sunrise is at 0600 and sunset is at 2000 (8PM). In the Spring and the Autumn, as we know, there are equal lengths of daylight and darkness, 12 hours of light and 12 hours of darkness (yes, true only at the exact moment of Spring and Autumn). 0600-2000 are more like summer hours of sunrise/sunset.
**The Fixes are Easy
Within the TimeOfDay file (RailSimulatorCore\TimeOfDay\Default.bin) tweaks can be made to fix these problems. You can either do it by creating a new blueprint (the preferred way) or tweaking the TimeOfDay file itself.
Sunrise/sunset times are easy to change. I have left sunrise the same (0600), but changed sunset to 1800 so we have equal times of sunlight and darkness to match the Spring season of the default TimeOfDay file.
To change the sun's and moon's sky traversal and have them travel across the southern sky instead of the northern, (again, only for routes in the northern hemisphere), make the azimuth values negative for both instead of positive.
In real life, the height of the sun above the horizon is dependent on your latitude of course. I run the Barstow-San Bernardino route almost exclusively, so I worked out the sun height to give approximately correct length shadows for Spring at that route's latitude (34 degrees north). A new azimuth value of -0.5000 is approximately correct. Make the moon the same if you like, as the moon and the sun travel in roughly the same ecliptic (the moon is 5 degrees higher at times). Noon sun now produces shorter shadows and a stark, more overhead light, more indicative of the route's latitude and desert area. I like its look. I had lived in this area of the country for years in the past and I find the new look more natural.
If you run a different route, say at latitudes of 40 degrees north, try setting the azimuth to something like -0.6000. For 50 degrees north, perhaps -0.7000. Experiment with shadow lengths at high noon. Check the shadow lengths on utility poles at that time. Be sure you have an equal period of daylight hours centered on 12 noon for the shadows to be shortest at noon. Remember, northern latitudes are negative azimuth numbers, and southern latitudes are positive azimuth numbers.
**Other Seasons
Of course the sun climbs higher in the noon sky in the summer and lower in the winter. The rise and set times vary as well, earlier and later. You can make a time of day file for each season if you want. Each season is specified for your route in the Routes.xml file. If you make a separate TimeOfDay file for each season, be sure each file has the correct season designation name within.
Like this:
<Season d:type="cDeltaString">SEASON_SPRING</Season>
<Season d:type="cDeltaString">SEASON_SUMMER</Season>
<Season d:type="cDeltaString">SEASON_AUTUMN</Season>
<Season d:type="cDeltaString">SEASON_WINTER</Season>
The changes for Barstow-San Bernardino:
Changes for the SUN:
<InfoSun>
<sSkyBodyInfo>
<RiseTime>
<sTimeOfDay>
<_iHour d:type="sInt32">6</_iHour>
<_iMinute d:type="sInt32">0</_iMinute>
<_iSeconds d:type="sInt32">0</_iSeconds>
</sTimeOfDay>
</RiseTime>
<SetTime>
<sTimeOfDay>
<_iHour d:type="sInt32">18</_iHour>
<_iMinute d:type="sInt32">0</_iMinute>
<_iSeconds d:type="sInt32">0</_iSeconds>
</sTimeOfDay>
</SetTime>
<AzimuthAngle d:type="sFloat32" d:alt_encoding="000000000000E0BF" d:precision="string">-0.5000</AzimuthAngle>
</sSkyBodyInfo>
</InfoSun>
Changes for the MOON:
<InfoMoon>
<sSkyBodyInfo>
<RiseTime>
<sTimeOfDay>
<_iHour d:type="sInt32">18</_iHour>
<_iMinute d:type="sInt32">0</_iMinute>
<_iSeconds d:type="sInt32">0</_iSeconds>
</sTimeOfDay>
</RiseTime>
<SetTime>
<sTimeOfDay>
<_iHour d:type="sInt32">6</_iHour>
<_iMinute d:type="sInt32">0</_iMinute>
<_iSeconds d:type="sInt32">0</_iSeconds>
</sTimeOfDay>
</SetTime>
<AzimuthAngle d:type="sFloat32" d:alt_encoding="000000000000E0BF" d:precision="string">-0.5000</AzimuthAngle>
</sSkyBodyInfo>
</InfoMoon>
Old sun at noon. Long shadows, darker, lower angle light.
http://img388.imageshack.us/img388/4066/old1fp0.th.jpg (http://img388.imageshack.us/my.php?image=old1fp0.jpg)
Old sun at noon. Long shadows, darker, lower angle light.
http://img84.imageshack.us/img84/4706/old2at2.th.jpg (http://img84.imageshack.us/my.php?image=old2at2.jpg)
New sun at noon. Shorter shadows, brighter, more direct overhead light.
http://img221.imageshack.us/img221/8332/new1ld1.th.jpg (http://img221.imageshack.us/my.php?image=new1ld1.jpg)
New sun at noon. Shorter shadows, brighter, more direct overhead light.
http://img84.imageshack.us/img84/7241/new2rg0.th.jpg (http://img84.imageshack.us/my.php?image=new2rg0.jpg)
**The Problems
1. Sky Traversal is Opposite from Normal
If a route is in the northern hemisphere, the sun and moon traverse the sky in the north instead of the south. Routes in the southern hemisphere are okay, because the sun and moon traverse the sky in the north where they should (yes, I know this is not true in certain seasons for latitudes between the equator and 23.5 degrees).
2. Shadow Length is too Short
Sun shadows are way too long for any given time of day. Shadows at high noon are as long as they would be at 3 or 4PM. This also limits the overall lighting at the noon hour since the sun is not as high above the horizon as it should be.
3. A Minor "Nit" Problem with Sunrise/Sunset Times
The TimeOfDay file (there is only one) is set up for Spring (SEASON_SPRING), I presume as a compromise for all seasons. Sunrise is at 0600 and sunset is at 2000 (8PM). In the Spring and the Autumn, as we know, there are equal lengths of daylight and darkness, 12 hours of light and 12 hours of darkness (yes, true only at the exact moment of Spring and Autumn). 0600-2000 are more like summer hours of sunrise/sunset.
**The Fixes are Easy
Within the TimeOfDay file (RailSimulatorCore\TimeOfDay\Default.bin) tweaks can be made to fix these problems. You can either do it by creating a new blueprint (the preferred way) or tweaking the TimeOfDay file itself.
Sunrise/sunset times are easy to change. I have left sunrise the same (0600), but changed sunset to 1800 so we have equal times of sunlight and darkness to match the Spring season of the default TimeOfDay file.
To change the sun's and moon's sky traversal and have them travel across the southern sky instead of the northern, (again, only for routes in the northern hemisphere), make the azimuth values negative for both instead of positive.
In real life, the height of the sun above the horizon is dependent on your latitude of course. I run the Barstow-San Bernardino route almost exclusively, so I worked out the sun height to give approximately correct length shadows for Spring at that route's latitude (34 degrees north). A new azimuth value of -0.5000 is approximately correct. Make the moon the same if you like, as the moon and the sun travel in roughly the same ecliptic (the moon is 5 degrees higher at times). Noon sun now produces shorter shadows and a stark, more overhead light, more indicative of the route's latitude and desert area. I like its look. I had lived in this area of the country for years in the past and I find the new look more natural.
If you run a different route, say at latitudes of 40 degrees north, try setting the azimuth to something like -0.6000. For 50 degrees north, perhaps -0.7000. Experiment with shadow lengths at high noon. Check the shadow lengths on utility poles at that time. Be sure you have an equal period of daylight hours centered on 12 noon for the shadows to be shortest at noon. Remember, northern latitudes are negative azimuth numbers, and southern latitudes are positive azimuth numbers.
**Other Seasons
Of course the sun climbs higher in the noon sky in the summer and lower in the winter. The rise and set times vary as well, earlier and later. You can make a time of day file for each season if you want. Each season is specified for your route in the Routes.xml file. If you make a separate TimeOfDay file for each season, be sure each file has the correct season designation name within.
Like this:
<Season d:type="cDeltaString">SEASON_SPRING</Season>
<Season d:type="cDeltaString">SEASON_SUMMER</Season>
<Season d:type="cDeltaString">SEASON_AUTUMN</Season>
<Season d:type="cDeltaString">SEASON_WINTER</Season>
The changes for Barstow-San Bernardino:
Changes for the SUN:
<InfoSun>
<sSkyBodyInfo>
<RiseTime>
<sTimeOfDay>
<_iHour d:type="sInt32">6</_iHour>
<_iMinute d:type="sInt32">0</_iMinute>
<_iSeconds d:type="sInt32">0</_iSeconds>
</sTimeOfDay>
</RiseTime>
<SetTime>
<sTimeOfDay>
<_iHour d:type="sInt32">18</_iHour>
<_iMinute d:type="sInt32">0</_iMinute>
<_iSeconds d:type="sInt32">0</_iSeconds>
</sTimeOfDay>
</SetTime>
<AzimuthAngle d:type="sFloat32" d:alt_encoding="000000000000E0BF" d:precision="string">-0.5000</AzimuthAngle>
</sSkyBodyInfo>
</InfoSun>
Changes for the MOON:
<InfoMoon>
<sSkyBodyInfo>
<RiseTime>
<sTimeOfDay>
<_iHour d:type="sInt32">18</_iHour>
<_iMinute d:type="sInt32">0</_iMinute>
<_iSeconds d:type="sInt32">0</_iSeconds>
</sTimeOfDay>
</RiseTime>
<SetTime>
<sTimeOfDay>
<_iHour d:type="sInt32">6</_iHour>
<_iMinute d:type="sInt32">0</_iMinute>
<_iSeconds d:type="sInt32">0</_iSeconds>
</sTimeOfDay>
</SetTime>
<AzimuthAngle d:type="sFloat32" d:alt_encoding="000000000000E0BF" d:precision="string">-0.5000</AzimuthAngle>
</sSkyBodyInfo>
</InfoMoon>
Old sun at noon. Long shadows, darker, lower angle light.
http://img388.imageshack.us/img388/4066/old1fp0.th.jpg (http://img388.imageshack.us/my.php?image=old1fp0.jpg)
Old sun at noon. Long shadows, darker, lower angle light.
http://img84.imageshack.us/img84/4706/old2at2.th.jpg (http://img84.imageshack.us/my.php?image=old2at2.jpg)
New sun at noon. Shorter shadows, brighter, more direct overhead light.
http://img221.imageshack.us/img221/8332/new1ld1.th.jpg (http://img221.imageshack.us/my.php?image=new1ld1.jpg)
New sun at noon. Shorter shadows, brighter, more direct overhead light.
http://img84.imageshack.us/img84/7241/new2rg0.th.jpg (http://img84.imageshack.us/my.php?image=new2rg0.jpg)