Trying to understand the inner workings of TileProxy

[Zippy1970]

By now I've read tons of forum posts, read the manual twice, and also read the tutorial a few times. And although they do explain the basics, they don't explain the inner workings of TileProxy much. As such, it's terribly difficult to troubleshoot problems since it's almost impossible to find out what's causing them.So please allow me to ask a few questions. Hopefully someone can answer them.At first I was terribly confused about the difference of "LOD" and "LEVEL". Stuff like "max_lod", "preload_min_lod", "preload_max_lod", "max_level", and "min_level".But as I understand it: LOD (Level of Detail) is what Flight Simulator uses internally. It ranges from 8 to 17. 8 Being the lowest level of detail and 17 being the highest. Acoording to the TileProxy manual, the LODs are:

LOD 8 = 304 m/p (meters per pixel)LOD 9 = 152 m/pLOD 10 = 76 m/pLOD 11 = 19 m/pLOD 12 = 9.5 m/pLOD 13 = 4.7 m/pLOD 14 = 2.4 m/pLOD 15 = 1.1 m/pLOD 16 = 0.6 m/pLOD 17 = 0.3 m/p

First of all, I don't think this is correct, but I will get back to this later.LEVEL refers to zoom levels on the map servers. Officially, they range from 1 to 19. Again, according to the manual, LOD 8 to LOD 17 corresponds to LEVEL 10 to LEVEL 19. So to be specific:

LOD 8 = LEVEL 10 = 304 m/p (meters per pixel)LOD 9 = LEVEL 11 = 152 m/pLOD 10 = LEVEL 12 = 76 m/pLOD 11 = LEVEL 13 = 19 m/pLOD 12 = LEVEL 14 = 9.5 m/pLOD 13 = LEVEL 15 = 4.7 m/pLOD 14 = LEVEL 16 = 2.4 m/pLOD 15 = LEVEL 17 = 1.1 m/pLOD 16 = LEVEL 18 = 0.6 m/pLOD 17 = LEVEL 19 = 0.3 m/p

Now the reason I think this is incorrect is because on map servers, an increase in level means a doubling of the resolution (because it splits the tiles in four). This means that LEVEL 12 (LOD 10) isn't 76 m/p, but 38 m/p and thus LEVEL 11 (LOD 9) is 76 m/p and LEVEL 10 (LOD 8) is 152 m/p. These zoom levels are confirmed by several documents on the internet. So if these levels truly are zoom levels, then the correct table is :

LOD 8 = LEVEL 10 = 152 m/p (corrected)LOD 9 = LEVEL 11 = 76 m/p (corrected)LOD 10 = LEVEL 12 = 38 m/p (corrected)LOD 11 = LEVEL 13 = 19 m/pLOD 12 = LEVEL 14 = 9.5 m/pLOD 13 = LEVEL 15 = 4.7 m/pLOD 14 = LEVEL 16 = 2.4 m/pLOD 15 = LEVEL 17 = 1.1 m/pLOD 16 = LEVEL 18 = 0.6 m/pLOD 17 = LEVEL 19 = 0.3 m/p

Anyway, this is just a side note since it has no impact whatsoever on how TileProxy works.Here are my real questions:Question 1: My first real question is about the different LOD related parameters. First the max_lod parameter. According to the manual, "max_lod is the highest LOD level for tiles that will be loaded generated". Yes, that's literally taken from the manual. So what exactly is it? The highest LOD level loaded, or the highest level generated? And loaded from where? From the internet? From the cache? What exactly does it limit? And what's the difference with preload_max_lod? So for instance, what happens if max_lod is set to 15, but preload_max_lod to 17? And what happens if we already have a higher LOD level in our cache? Will it ignore anything higher than max_lod?Question 2: How does TileProxy look for tiles? Does it first look in the bitmap folder (TileProxy PhotoReal World) to see if the tiles are already available? Or does it look in the cache folder (cache.serviceX) first and always regenerate the bitmaps? Or does it always do a HTTP request first (for instance, a HEAD request) to see if the tile has changed since the last time it was downloaded?The reason I'm asking is because since I've discovered TP about a week ago, I've been doing the same flight over and over again. I take off from the same airport, and make the same little 10 mile circle at the same speed and height. But when it starts preloading tiles after I first startup FSX (so before the flight has actually started), sometimes it loads very fast (up to 800 tps), while other times it's incredibly slow (less than 10 tps). If it's loading those tiles from the cache (which it should), it should always be very fast. Likewise, when I start flying, sometimes it can keep up easily (pre-) loading tiles (again, as it should since all those tiles are in the cache), while other times I need to pause and wait for several minutes for the tiles to catch up.I have quite a few more questions, but let's start with these two first. :(

Edited February 25, 2012 by Zippy1970

[Zippy1970]

Ok, since this forum appears to be, ehm, not breathing, can anyone offer me suggestions for other places where I can ask my (TileProxy related) questions?Or is TileProxy simply too old? And if so, is there a (better) alternative for Europe scenery?Also, is TileProxy abandoned by the developer or is he still lurking somewhere?