Active sceneries and regeneration of airport cache

[Rafal]

Dear Umberto,

To begin with, this is not any kind of criticism as I am a big fan of GSX and use it all the time.
Once I moved from FS9 to FSX over a year ago I didn't even look back at AES I had used for many years.

Now the question is about the airport cache regeneration. Let me describe the situation as briefly as I can.
I guess most GSX users know this message line:



I, like many others here, use PMDG NGX and 777 on a daily basis. We all know how fantastic they are but also how demanding on performance they happen to be (due to all the systems, animations, etc).
In order to reduce the probability of getting an OOM on finals there are many recommendations to follow, some of the given by the PMDG team themselves.
One of them is deactivating the scenery addons which are not used in a given flight. For many that must be something new. At least it was for me, as I have always had a lot of airports installed and active all the time.

But now more and more knowledgeable simmers and developers, including PMDG's Ryan, suggest the activated sceneries do matter in performance management.
All in all it seems logical as for example flying from Istanbul to London I will overfly at least a few (usually more than that) active sceneries.
They say it particularly refers to addons including photoscenery as this will always load into FSX VAS no matter where in the world you currently fly.
On the other hand now a lot of payware airports released today include some or a lot of photoscenery, don't they?

Long story short, before each flight I deactivate all airports except the two I am going to fly between.
You may call it a delusion only, but I swear it has noticeably reduced my OOMs and even OOM pings (from FSUIPC) on arrival to larger sceneries.

Now what does it have to do with GSX? Well, looks like this technique, correct me if I'm wrong, has a visible side effect.
GSX has to regenerate the scenery cache each time. Why is it a problem? Well first of all it takes quite a lot of time. In my case it is usually a few minutes.
This is a pity since I have a habit to power up the cockpit (takes a few seconds) and start the ground services. Now I have to wait till all the regeneration ends.  

Secondly, to be aware what the problem with no GSX services is, I had to enable the GSX messages, which I always hide in FSX (text messages of any kind spoil the immersion for me).
Seeing them I am able to know the lack of services I am experiencing is due to the need of waiting for regeneration or (described later below) because of problems with reading the AFCAD.

And finally, but this does not happen in all cases (sometimes it does, sometimes it doesn't) after the regeneration ends I get another message there is an AFCAD problem and this stand has no services.
First I thought that must be and AFCAD problem since it says so. But I discovered that when I exit FSX and start up again at the same stand, this... no longer is a problem and I do get the services!  
Such situation has happened recently at several airports. Some of them where (unfortunately I did not note it anywehere) Aerosoft Bergen X, Aerosoft LEPA or FSDG Djerba.

Now my questions are:
1. What do you, as one the market's best scenery developers (in my view), think of deactivating scenery to improve VAS management?
2. Is there (forgive my non-developer's ignorance) any chance not to have the GSX airport cache regeneration each time?
3. What could be the 'problem' with GSX not reading an AFCAD's parking position once it can read it on another FSX session?

Once again let me underline the fact I LOVE GSX and what I am describing here will not change it.
Thanks a lot for reading my long post and for any reply.

All the best,
Rafal

[streichholz]

First of all, if you don't use the Scenery Config Editor, start to use it. Believe me, it makes the activation/de-activation a lot more easier and you may have not start the FSX again because you do it with FSX off. http://sourceforge.net/projects/fs-sceditor/

And you are right. The VAS decrease by deactivate it in the scenery library. I think we have to deal with the regenerating, because every time you change the library, new AFCADs will be activated too and GSX must read the new AFCADs, otherwise you will have wrong vehicle positions.

But I want to add a question. Is it true that the "texture_max_load = xxxx" will NOT affect the VAS? Because I thought the texture_max_load will affect the VAS?!

[Rafal]

Is it true that the "texture_max_load = xxxx" will NOT affect the VAS?

As fas as I understand, it matters only if you really intend to use UHD textures.
Even if you set it to 4096 in your fsx.cg, it won't do anything once you don't use such high res textures (it only tells the sim what the maximum resolution texture to load is).
I don't. I realize I lose quite some eye candy with the way the new airports may look with Flightbeam, Flytampa, FSDT or Aerosoft, but at least I may finish a flight on my rig. 

[streichholz]

Does the T7 use 4096?

[virtuali]

1. What do you, as one the market's best scenery developers (in my view), think of deactivating scenery to improve VAS management?

You might save some memory, yes, because sometimes FSX doesn't entirely reclaim memory used by sceneries, or tries to load sceneries that don't really belong to the area you are flying. At least, you can be sure is not happening with our sceneries ( and Flightbeam's ), because we basically don't use .BGL anymore, except for very minor things, but the bulk of the scenery

2. Is there (forgive my non-developer's ignorance) any chance not to have the GSX airport cache regeneration each time?

GSX is not regenerating the cache each time. It does it only when the Scenery Library changes, just like FSX. So, the question is not really relevant to GSX, because if you keep changing the scenery library, FSX will also regenerate its own cache. In fact, what's really triggering the GSX cache regeneration, is the FSX own regeneration.

So no, even if there was a way to prevent this ( and there isn't ), it would be a moot point, because FSX would regenerate its own cache too.

Secondly, to be aware what the problem with no GSX services is, I had to enable the GSX messages, which I always hide in FSX (text messages of any kind spoil the immersion for me). Seeing them I am able to know the lack of services I am experiencing is due to the need of waiting for regeneration or (described later below) because of problems with reading the AFCAD.

It really seems you want to have your cake and eat it too...you want to be informed, but the information spoils your immersion. Either be informed with useful messages, or stay in the dark having to guess what's happening. It's really your choice.

3. What could be the 'problem' with GSX not reading an AFCAD's parking position once it can read it on another FSX session?

This shouldn't happen. If it does, try a "Restart Couatl" command, perhaps you were too hasty trying to activate services, so the cache wasn't really ready.

[voodoo101]

There is a rumour going around that setting FSX config to 4096 textures actually helps FSX with OOM's, this is because it loads everything at the highest settings without having to rescale them. This saves on memory usage.

Turning off sceneries that you do not use vastly improves with VAS usage. Another thing to change is the LOD level, make sure that this is 4.5 for the 777. It can be higher for smaller aircraft. There is a program that is free called SimStarter that allows you to set up different profiles for different aircraft.

Virtuali, I'm sorry to say that you are wrong in your assumption that GSX is regenerating because FSX is regenerating the cache of the scenery. FSX will only re-cache the scenery if scenery is deleted or installed. It does not care if it is turned off or on, if it is off then it will just not load it.

Would it not be just as simple to have GSX cache the scenery on first install automatically, then have an option for the user to regenerate the cache if they change an AFCAD or install new scenery, does it have to be automated. Surely once it has read the airports, if it is turned off and you are not sat at a gate at that airport, GSX does not really care.

[boilerbill]

There is a new program from FSPS called FSX Fiber Acceleration that is designed for just the sort of problems described here. Basically it acts like a live scenery configuration editor that tweaks your fsx.cfg file on the fly, without actually changing that file. Although I was a bit skeptical, I agreed to try it out for a couple of friends on my computer. They had been experiencing OOMs when using the ConcordeX, which is a very complex aircraft. (I should mention here that I don't have any OOM problems with any of my aircraft, including the ConcordeX and the PMDG 777. I'm very happy with my FSX setup just as it is.) After a couple of days of testing, I had to admit that the program does exactly what it claims to do. One of the friends has purchased it and has had great results so far. The other friend is ordering it in the next couple of days. I also found that it had no effect on GSX at either end of the flight.

If you're as leery as I was, then have a look at a couple of YouTube videos that show FSX Fiber Acceleration in action. Their reactions were positive as ours. Also, you can try FSX Fiber Acceleration before you buy it. You can download a trial copy that gives you 5 trial sessions of 60 minutes duration.

[virtuali]

There is a rumour going around that setting FSX config to 4096 textures actually helps FSX with OOM's, this is because it loads everything at the highest settings without having to rescale them. This saves on memory usage.

The rumor is wrong, FSX doesn't "scale" anything by itself, either up or down.

- If the texture resolution is set at 4096, sceneries/airplane that don't use this resolution will stay at 1024.

- If the scenery/airplane *does* use textures at 4096 and FSX is set at 4096, it will just take that.

- If the scenery uses 4096, but you set FSX at 2048, or 1024, or even lower, FSX won't again scale anything: it will just take the next lower mip-map that has been precalculated and is already included in the DXT file, it will just ignore the highest mip-maps so no, is exactly the opposite of the rumour: in this case there WILL be some memory saving, because the higher resolution mip-map will be ignored.

- If the DXT file doesn't have Mip-maps, what will happen depends by the settings on the video card: if it has been configured to automatically generate mip-maps, the *CARD* will create automatically mip-maps on the fly, but that will just use exactly the same amount of memory as if the mip-map was already included in the DXT file, just the card will take a bit more time to load the texture, but VRAM (and, eventually, VAS allocation if under DX9) will be the same. If, instead, the card is not configured to generate mip-maps automatically, you might have a bit of VRAM memory saving, but with moire effects and dancing pixels, because of the lack of mip-maps.

The only kind of textures that FSX generates and "scale" on the fly, depending on the resolution set, are Landclasses + Vector data, but they won't go higher than 1024x1024, so they are entirely unaffected by settings higher than that.

The only case where you can save some memory, is to set the texture resolution to be LESS than 1024, so Landclass + Vector data generation will be faster and will take less memory, but I doubt anyone use FSX with that kind of setting anymore.

Virtuali, I'm sorry to say that you are wrong in your assumption that GSX is regenerating because FSX is regenerating the cache of the scenery. FSX will only re-cache the scenery if scenery is deleted or installed. It does not care if it is turned off or on, if it is off then it will just not load it.

Just tried now, turning on/off a scenery using the Scenery Library in FSX, and I can see the FSX progress about the cache regeneration both when I turn off a scenery which was on, and I can see it again when turning it back on. The following cache regeneration in GSX was quick too.

But even if you haven't noticed the progress bar ( I can see it easily ), just check the C:\ProgramData\FSX\Facilities folder, turning on or off an area in the Scenery Library in FSX will result in all files in that folder to change their last modification date, and some of them (depending what the scenery contained) will also change their size, meaning there will always be some files in FSX are being regenerated, even by simply turning on/off an area, even if you haven't noticed the progress bar. GSX simply follows the regeneration of FSX, when any of these files are being changed.

Would it not be just as simple to have GSX cache the scenery on first install automatically, then have an option for the user to regenerate the cache if they change an AFCAD or install new scenery, does it have to be automated.

Yes, it must be automated, because if an user forget to regenerate it manually, it will come here saying that GSX is not working, and we'll have to repeat, endlessly, "have you regenerated the cache ?" Cumbersome and annoying.

[anappy]

I have all these same issues. Maybe it's time for a service pack, this didn't use to happen, seeing as multiple people have this issue clearly fsdreamteam changed something to make it more irritable to use. 

[Rafal]

Dear Umberto,

First of all thank you for replying to my post.
I appreciate developers talking to their customers.

you can be sure is not happening with our sceneries ( and Flightbeam's ), because we basically don't use .BGL anymore, except for very minor things, but the bulk of the scenery

Wow, great, I did not know to be honest.
I won't be activating/deactivating FSDT/FB sceneries then (and I have most of them).

GSX is not regenerating the cache each time. It does it only when the Scenery Library changes, just like FSX

All right, I understand. So maybe the question is do you think it might be possible to make this process faster in a future version of GSX?
For comparison, I have just tried deactivating/activating one airport in the scenery library. FSX have rebuilt its cache in 7 seconds. For GSX it took 8 minutes.

try a "Restart Couatl" command, perhaps you were too hasty trying to activate services, so the cache wasn't really ready

OK, thanks, I will keep an eye on that.

Have a great Sunday,
Rafal

[virtuali]

I have all these same issues.

There are no "issues" to begin with. As I've said already, GSX regenerate its cache when FSX regenerates its own.

Maybe it's time for a service pack

You mean another FSX service pack that would stop regenerating the FSX cache ? Because, again, GSX regenerate its cache in parallel with FSX.

this didn't use to happen, seeing as multiple people have this issue clearly fsdreamteam changed something to make it more irritable to use.

It's always been like this since GSX has been released, and nothing has changed. What has changed is:

1) Because of some too memory-hungry airplanes, uses are forced to play more with the Scenery Library, hoping to save from VAS. The real culprit, of course, is the memory-hungry airplane. Hint: if airplane developers would start to use the same technique as we do with our stuff ( Couatl is an *external* programming engine, so it doesn't take away a single bit of precious VAS from FSX ), we wouldn't have so much of VAS exhaustions problems to begin with, that would require to keep acting on the Scenery Library before each flight.

2) P3D is more popular now, and many users have both P3D and FSX installed on the same system. If the two sims are running on the same Windows installation, the GSX airport cache is shared between the two, which means if you alternate between sims, the cache will be regenerated each time. We WILL have two independent caches for the two sim in the next update, so this specific issue will go away.