PhotoScenery in P3D?

[Dougal 165]

Does photosceney in P3D do the same as FSX, as in all load at start up?

[Jim Young 2,356]

Hi Phil,

 

All photoscenery that is activated in the Scenery Library will load.  The loading begins at startup.

 

Best regards,

Jim

[downscc 1,327]

My photoscenery files only load when I am in vicinity of the scenery.  A load of all photosceneries globally at the startup is not happening in my setup. I'm not sure what might be the difference.

 

I first noticed this with Fly Tampa sceneries that have large photo bgl files at Midway and Montreal.  I could watch VAS load increase then decrease as I approached and passed the area... and setting those bgls to bgl.off got rid of the impact.

[Jim Young 2,356]

 

 

My photoscenery files only load when I am in vicinity of the scenery. A load of all photosceneries globally at the startup is not happening in my setup. I'm not sure what might be the difference.

 

Hi Dan,

 

That is strange.  I think you have to have a lot of photoscenery enabled to really see the effects of the loading. The PMDG 777 Introduction Guide, page 31 also states what I stated (believe Tabs wrote this guide) about photoscenery.  I discovered this phenomenom when I bought all of the US States MSE series (well, 41 of them at least) and enabled them all.  At the time I was using FSX and FSX started loading all of them immediately and I heard a lot of thrashing on the mechanical HDD containing the sceneries.  The aircraft at startup were black until sufficient resources were released to render them and it took forever to load to the beginning of the flight.  The sim nearly crashed.  It might as well crashed as I could do nothing but listen to the loading of the scenery.  At first I had no idea what was causing it until I disabled all of the photoscenery.  Then FSX/P3D started up immediately.  I now only enable photoscenery I will be using during my flight session.

 

I also put the information in my AVSIM FSX Configuration and CTD Guides to warn others of this issue.  You can run Process Monitor using the suggested setup I placed in the AVSIM CTD Guide, page 16.  If you set it up correctly, it will show you everything loading when you start up P3D (or FSX, FSX-SE, X-Plane) and then during the flight.  It gives you a good idea as to what you should disable that might be taking up VAS resources unnecessarily.

 

Best regards,

Jim

[Kuragiman 227]

Photoreal attached to an airport scenery file is not the same as Photoscenery of a state/country level.   Entire state packages are loaded into memory on start up.   It's why the sim takes 2-4 minutes to load instead of loading in under 30 seconds with landclass.  The PS for the airport is loaded in at the start for the departure runway but dumps after you are away from the airport but the state of Iowa 400 miles back does not.  It will be loaded in and ready to go.    This is confirmed on my system where my VAS doesn't change at all except for when I am leaving the depature airport or arriving at my destination airport.  Everything in between stays a pretty solid number.

[downscc 1,327]

Photoreal attached to an airport scenery file is not the same as Photoscenery of a state/country level.

 

Thanks for that, I did not know that. My ignorance is showing.

I do know that  the 471MB photo bgl in the Montreal Scenery folder is a VAS killer when overflying.... so I assumed all photo bgls were the same. Bad assumption I guess.

 

I also assumed we were talking specifically about P3D, and that it treated photo bgls differently from FSX.  Again, my error was thinking one bgl was like another.

[Kuragiman 227]

 

 

I also assumed we were talking specifically about P3D, and that it treated photo bgls differently from FSX.  Again, my error was thinking one bgl was like another.

 

As far as I know, FSX and P3D treat photoscenery the same.   I have all 50 states of MegaSceneryEarth 2.0 and some of their Ultra-Res Cities.   Those states stay in memory regardless of how far away you are from them.  This is why it is highly highly recommended you never load an entire country into your sim unless it is a small country.    For the US, I can turn on about 6-8 states at once depending on how big the state is and still have a good 500-600 megs of VAS left at the end of the flight.     What I do is build my flight plan in SimBrief or PFPX, look at what states my path flies over and then use SceneryConfigurationManager to load just those states I am going over and turn all the others off.    Works like a charm.    Takes about 2 minutes for the simulator to load in with all those states on.   That load time speeds up if you have loaded the state before since all the Shader files are now built and ready to go for that state.

[Christopher Low 5,331]

What exactly is it that is loaded when photoscenery is enabled? My UK VFR Photographic Scenery occupies nearly 300GB of hard disk space, so clearly it isn't the photoscenery files themselves.

[kevinfirth 1,392]

What exactly is it that is loaded when photoscenery is enabled? My UK VFR Photographic Scenery occupies nearly 300GB of hard disk space, so clearly it isn't the photoscenery files themselves.

Chris you must be right since the size of the files way exceeds the VAS limit it cannot be the actual bgl files themselves. I speculate that the sim is in fact indexing the photoscenery bgls at startup. It cannot be true that photoscenery does not unload from VAS either, since logically the 4Gb limit would be exceeded extremely quickly, and certainly in my experience that is not the case. However, when the sim loads data into VAS it requires contiguous free space to do so, which explains several phenomena.

1. That you can OOM without actually reaching the 4Gb limit. If you have 500k VAS remaining free but it is in 5 separate chunks of 100k for example, then your destination airport tries to load a 101k texture, you can OOM with 399k VAS technically unused...

2. This also could explain the photoscenery observations, since PR bgls are generally much larger than LC textures, they can possibly build up and be allocated space within our 4Gb VAS space in such a way that there is no contiguous free space for further large files.

The solutions are several-fold. Photoscenery can be optimised, eg Horizon is divided into 1.2m and 2.4m layers, which helps to minimise the VAS requirements for PR tiles further away from you. Scenery can also be compiled with a greater degree of compression. The sim itself can unload unused data more effectively, as well as possible manage the data it does hold more efficiently to maximise that contiguous free space, or the VAS limit can be raised by moving to 64bit.